Re: [Wien] proper k-points for Nd

[Victor Zenou]

Thanks Pandey for your kind help.

Actually 60,000 k-points done parallel without iterative
denationalization gave the ENERGY convergence better than ~5X10^-8 and
charge convergence better than 9*10^-5. Basically, same magnetic moment.
(E=-77040.4697676 Ryd; MMTOT=16.645).

But your calculations were done more efficiently, so 6000 k-points were
enough.

Dear Laurie, I used the RMT for few other phases with RTM(Nd)=2.7. That's
why I wanted to stay with the same large RMT. I did try RMT(Nd)=2.5, with
HDLOs for d and f electrons and got the same energy warning. I'm not sure
what's happened, but right now I plan to repeat k-test with RMT(Nd)=2.5,
better charge convergence (maybe even cc 0.1 as was done by Pandey) and
without iterative denationalization.

 “Failure is instructive. The person who really thinks learns quite as much
from his failures as from his successes.” ― *John Dewey*

‫בתאריך יום ו׳, 25 בינו׳ 2019 ב-1:32 מאת ‪Tribhuwan Pandey‬‏ <‪
tribhuwan.phys...@gmail.com‬‏>:‬

> Dear Victor, and Wien2k developers,
>
> I recently ran some calculations on bulk Nd, and I thought of adding some
> points to this discussion. There are few differences between mine and
> Victor's calculations: I am using *wien2k-14.1 (built with intel compiler
> and fftw), APW basis*, *Nd RMT: 2.44, RKmax: 9.33, and GMax = 12.0*
>
> I first ran the calculations with -cc 0.0001, once calculations was
> converged  to eliminate the possibility of false convergence, I cranked it
> up to 0.1.
>
> Below it the convergence with respect to K points:
>
> K-points in the full  Energy (RyD)
>
> Bz   MMTOT
>  300-77040.4784888916.54268
> 1200-77040.47806017
> 16.75716
> 6000-77040.47815237
> 16.79681
> 12000  -77040.47815397
> 16.80318
> 24000  -77040.4781510316.80044
> 3   -77040.4781500716.80171
> 36000   -77040.4781495216.80263
>
>
> In my calculations energy convergences reasonably well (0.01 meV)  with
> respect to  K-points.
>
> PS. Victor, I am sharing my files at this link
>
>
> https://drive.google.com/file/d/1rOKoRph6zVAkgAUjc64-Xgi6av3XmdSU/view?usp=sharing
>
> if it helps to track down the issue. Not sure if your problem occurs from
> the different wien versions, which is quite unlikely.
>
> Hope it helps.
>
> Thanks
> Pandey
>
> --
> 
> 
> Tribhuwan Pandey, Ph. D
> Postdoctoral Research Associate
> Condensed Matter Theory Group
> Materials Science and Technology Division
> Oak Ridge National Laboratory, Oak Ridge, USA
> _
> _
>
>
>
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Re: [Wien] proper k-points for Nd

[Lyudmila Dobysheva]

25.01.2019 3:32, Tribhuwan Pandey wrote:

*Nd RMT: 2.44* RKmax: 9.33,

18.01.2019 0:19, Victor Zenou wrote:
> I used RMT=2.7 a.u. RMT*Kmax=8.5

Besides difference in Rkmax, there is a difference in Rmt between 
Pandey's and Victor's calculation. Could this large Rmt be the main reason?


Best wishes
Lyudmila Dobysheva
--
Physics-Techn.Institute,
Udmurt Federal Research Center, Ural Br. of Rus.Ac.Sci.
426000 Izhevsk Kirov str. 132
Russia
---
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Re: [Wien] proper k-points for Nd

[Tribhuwan Pandey]

Dear Victor, and Wien2k developers,

I recently ran some calculations on bulk Nd, and I thought of adding some
points to this discussion. There are few differences between mine and
Victor's calculations: I am using *wien2k-14.1 (built with intel compiler
and fftw), APW basis*, *Nd RMT: 2.44, RKmax: 9.33, and GMax = 12.0*

I first ran the calculations with -cc 0.0001, once calculations was
converged  to eliminate the possibility of false convergence, I cranked it
up to 0.1.

Below it the convergence with respect to K points:

K-points in the full  Energy (RyD)
   Bz
MMTOT
 300-77040.4784888916.54268
1200-77040.4780601716.75716

6000-77040.47815237 16.79681
12000  -77040.4781539716.80318
24000  -77040.4781510316.80044
3   -77040.4781500716.80171
36000   -77040.4781495216.80263


In my calculations energy convergences reasonably well (0.01 meV)  with
respect to  K-points.

PS. Victor, I am sharing my files at this link

https://drive.google.com/file/d/1rOKoRph6zVAkgAUjc64-Xgi6av3XmdSU/view?usp=sharing

if it helps to track down the issue. Not sure if your problem occurs from
the different wien versions, which is quite unlikely.

Hope it helps.

Thanks
Pandey

-- 


Tribhuwan Pandey, Ph. D
Postdoctoral Research Associate
Condensed Matter Theory Group
Materials Science and Technology Division
Oak Ridge National Laboratory, Oak Ridge, USA
_
_
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Re: [Wien] proper k-points for Nd

[Laurence Marks]

his is not
>> true.
>> > In reality dft problems have stacks of numerical issues which leads to
>> > "noise". You can think about this in terms of finding the minimum of
>> > "F(x) = x*x + Constant*Noise(x)" where Noise(x) is some randomly
>> > generated noise. The larger Constant is, the larger the deviation is
>> > from x=0 of the apparent minimum. Averaging over more k-points may
>> > reduce Constant, but often in my experience does relatively little.
>> >
>> > A symptom of noise is poor convergence -- which is clearly what is
>> > occurring here.
>> >
>> > If you improve the convergence rate you will reduce the noise. Some
>> > suggestions:
>> >
>> > 1) Use HDLO and reduce RMT
>> > 2) Reduce RMT and use HDLO
>> > 3) Larger LM (e.g. 8)
>> > 4) Larger gmax in case.in2 (e.g. 16)
>> > 5) Use TEMPS 0.0018 (room temperature)
>> > 6) Peter's suggestions
>> >
>> > On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at
>> > <mailto:t...@theochem.tuwien.ac.at> > > <mailto:t...@theochem.tuwien.ac.at>> wrote:
>> >
>> > Hi,
>> >
>> > If not too expensive, you could try more k-points (2 and 25000)
>> > to see if the fluctuations persist.
>> >
>> > Questions: how many atoms in the unit cell? Are you optimizing the
>> > position of atoms?
>> >
>> > F. Tran
>> >
>> > On Sunday 2019-01-20 17:17, Victor Zenou wrote:
>> >
>> >  >Date: Sun, 20 Jan 2019 17:17:55
>> >  >From: Victor Zenou > > <mailto:za...@post.bgu.ac.il>>
>> >  >Reply-To: A Mailing list for WIEN2k users
>> > > > <mailto:wien@zeus.theochem.tuwien.ac.at>>
>> >  >To: A Mailing list for WIEN2k users
>> > > > <mailto:wien@zeus.theochem.tuwien.ac.at>>
>> >  >Subject: Re: [Wien] proper k-points for Nd
>> >  >
>> >  >Dear Peter, LDM and wien2k users
>> >  >I did some more calculation with energy and CHARGE convergence
>> > criteria
>> >  >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
>> > converged to
>> >  >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
>> > 4*10-2 Ryd
>> >  >(please see below)
>> >  >I didn't check AFM yet, but this is not the point. The point is
>> to get
>> >  >"stable" calculation for optimal k-points.
>> >  >I have to say that for each calculation I totally aresed all file
>> > except
>> >  >case.struc.
>> >  >Also I used all defaults as well as gmax=12, also
>> > rmt(min)*kmax=8.5, for all
>> >  >calculations.
>> >  >I can repeat all calculation with smaller RMT, such as 2.5, or to
>> > check
>> >  >HDLO.
>> >  >I think I will start with smaller RMT. Any comments / suggestions?
>> >  >Victor
>> >  >
>> >  >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE
>> MMTOT
>> >  >3000 208 -77040.50516761 -.000504 0.000825   16.00318
>> >  >5000 280 -77040.48748499 -.000544 0.000758   16.68523
>> >  >7500 455 -77040.51668342 -.000862 0.000183   16.62547
>> >  >1 540 -77040.48747210 -.000817 0.000499   16.67544
>> >  >15000 840 -77040.46976815 -.000216 0.001362   16.64536
>> >  >
>> >  >
>> >  >
>> >
>> >
>> >
>> > --
>> > Professor Laurence Marks
>> > "Research is to see what everybody else has seen, and to think what
>> > nobody else has thought", Albert Szent-Gyorgi
>> > www.numis.northwestern.edu <http://www.numis.northwestern.edu> ;
>> > Corrosion in 4D: MURI4D.numis.northwestern.edu
>> > <http://MURI4D.numis.northwestern.edu>
>> > Partner of the CFW 100% program for gender equity,
>> > www.cfw.org/100-percent
>> <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.cfw.org_100-2Dpercent&d=DwMFaQ&c=yHlS04HhBraes5BQ9ueu5zKhE7rtNXt_d012z2PA6ws&r=U_T4PL6jwANfAy4rnxTj8IUxm818jnvqKFdqWLwmqg0&m=28Unab2_PMhNTfCBOLqfcq1inwyHdbI_dlCMNvwLK84&s=yDtS64Gn0BW5LZtci1IGnXikcYkizDD22CCZKQJssmA&e=>
>> <http://www.cfw.org/100-percent
>> <https://urldefense.proofpoint.com/

Re: [Wien] proper k-points for Nd

[Victor Zenou]

20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at
> > <mailto:t...@theochem.tuwien.ac.at>  > <mailto:t...@theochem.tuwien.ac.at>> wrote:
> >
> > Hi,
> >
> > If not too expensive, you could try more k-points (2 and 25000)
> > to see if the fluctuations persist.
> >
> > Questions: how many atoms in the unit cell? Are you optimizing the
> > position of atoms?
> >
> > F. Tran
> >
> > On Sunday 2019-01-20 17:17, Victor Zenou wrote:
> >
> >  >Date: Sun, 20 Jan 2019 17:17:55
> >  >From: Victor Zenou  > <mailto:za...@post.bgu.ac.il>>
> >  >Reply-To: A Mailing list for WIEN2k users
> >  > <mailto:wien@zeus.theochem.tuwien.ac.at>>
> >  >To: A Mailing list for WIEN2k users
> >  > <mailto:wien@zeus.theochem.tuwien.ac.at>>
> >  >Subject: Re: [Wien] proper k-points for Nd
> >  >
> >  >Dear Peter, LDM and wien2k users
> >  >I did some more calculation with energy and CHARGE convergence
> > criteria
> >  >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
> > converged to
> >  >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
> > 4*10-2 Ryd
> >  >(please see below)
> >  >I didn't check AFM yet, but this is not the point. The point is to
> get
> >  >"stable" calculation for optimal k-points.
> >  >I have to say that for each calculation I totally aresed all file
> > except
> >  >case.struc.
> >  >Also I used all defaults as well as gmax=12, also
> > rmt(min)*kmax=8.5, for all
> >  >calculations.
> >  >I can repeat all calculation with smaller RMT, such as 2.5, or to
> > check
> >  >HDLO.
> >  >I think I will start with smaller RMT. Any comments / suggestions?
> >  >Victor
> >  >
> >  >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
> >  >3000 208 -77040.50516761 -.000504 0.000825   16.00318
> >  >5000 280 -77040.48748499 -.000544 0.000758   16.68523
> >  >7500 455 -77040.51668342 -.000862 0.000183   16.62547
> >  >1 540 -77040.48747210 -.000817 0.000499   16.67544
> >  >15000 840 -77040.46976815 -.000216 0.001362   16.64536
> >  >
> >  >
> >  >
> >
> >
> >
> > --
> > Professor Laurence Marks
> > "Research is to see what everybody else has seen, and to think what
> > nobody else has thought", Albert Szent-Gyorgi
> > www.numis.northwestern.edu <http://www.numis.northwestern.edu> ;
> > Corrosion in 4D: MURI4D.numis.northwestern.edu
> > <http://MURI4D.numis.northwestern.edu>
> > Partner of the CFW 100% program for gender equity,
> > www.cfw.org/100-percent <http://www.cfw.org/100-percent>
> > Co-Editor, Acta Cryst A
> >
> > ___
> > Wien mailing list
> > Wien@zeus.theochem.tuwien.ac.at
> > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> > SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
> >
>
> --
> --
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
> Email: bl...@theochem.tuwien.ac.atWIEN2k: http://www.wien2k.at
> WWW:
>
> http://www.imc.tuwien.ac.at/tc_blaha-
>
> ___
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Re: [Wien] proper k-points for Nd

[Laurence Marks]

I think Peter tends to use -it; I prefer -it -noHinv which may behave
better but I will agree is not great for f systems (even for surfaces) and
may not speed up the calculation measured by total time as against time per
iteration.

On Tue, Jan 22, 2019 at 3:00 PM Peter Blaha 
wrote:

> Please, do NOT use iterative diagonalization 
>
> Iterative diagonalization is for "few eigenvalues and large cells" (like
> surfaces, or supercells where every atoms has only few electrons.
>
> Iterative diagonalization is NOT for f-systems !!
> Firstly, you will not get any speedup, but even worse, the
> diagonalization and scf-convergence may not finish at the same time,
> i.e. your eigenvalues/verctors are wrong.
>
> (-it explains why you get ghostbands when changing the k-mesh (should
> use -it1 or touch .fulldiag), and also explains why you get so different
> energies. These numbers are simply not converged.
>
>
> --
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu
Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent
Co-Editor, Acta Cryst A
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Re: [Wien] proper k-points for Nd

[Peter Blaha]

d, so have "simple" fixed-point solutions. In fact this is
not true.
 > In reality dft problems have stacks of numerical issues which
leads to
 > "noise". You can think about this in terms of finding the minimum of
 > "F(x) = x*x + Constant*Noise(x)" where Noise(x) is some randomly
 > generated noise. The larger Constant is, the larger the deviation is
 > from x=0 of the apparent minimum. Averaging over more k-points may
 > reduce Constant, but often in my experience does relatively little.
 >
 > A symptom of noise is poor convergence -- which is clearly what is
 > occurring here.
 >
 > If you improve the convergence rate you will reduce the noise. Some
 > suggestions:
 >
 > 1) Use HDLO and reduce RMT
 > 2) Reduce RMT and use HDLO
 > 3) Larger LM (e.g. 8)
 > 4) Larger gmax in case.in2 (e.g. 16)
 > 5) Use TEMPS 0.0018 (room temperature)
 > 6) Peter's suggestions
 >
 > On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at
<mailto:t...@theochem.tuwien.ac.at>
 > <mailto:t...@theochem.tuwien.ac.at
<mailto:t...@theochem.tuwien.ac.at>> mailto:t...@theochem.tuwien.ac.at>
 > <mailto:t...@theochem.tuwien.ac.at
<mailto:t...@theochem.tuwien.ac.at>>> wrote:
 >
 >     Hi,
 >
 >     If not too expensive, you could try more k-points (2 and
25000)
 >     to see if the fluctuations persist.
 >
 >     Questions: how many atoms in the unit cell? Are you
optimizing the
 >     position of atoms?
 >
 >     F. Tran
 >
 >     On Sunday 2019-01-20 17:17, Victor Zenou wrote:
 >
 >      >Date: Sun, 20 Jan 2019 17:17:55
 >      >From: Victor Zenou mailto:za...@post.bgu.ac.il>
 >     <mailto:za...@post.bgu.ac.il <mailto:za...@post.bgu.ac.il>>>
 >      >Reply-To: A Mailing list for WIEN2k users
 >     mailto:wien@zeus.theochem.tuwien.ac.at>
 >     <mailto:wien@zeus.theochem.tuwien.ac.at
<mailto:wien@zeus.theochem.tuwien.ac.at>>>
 >      >To: A Mailing list for WIEN2k users
 >     mailto:wien@zeus.theochem.tuwien.ac.at>
 >     <mailto:wien@zeus.theochem.tuwien.ac.at
<mailto:wien@zeus.theochem.tuwien.ac.at>>>
 >      >Subject: Re: [Wien] proper k-points for Nd
 >      >
 >      >Dear Peter, LDM and wien2k users
 >      >I did some more calculation with energy and CHARGE convergence
 >     criteria
 >      >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
 >     converged to
 >      >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
 >     4*10-2 Ryd
 >      >(please see below)
 >      >I didn't check AFM yet, but this is not the point. The
point is to get
 >      >"stable" calculation for optimal k-points.
 >      >I have to say that for each calculation I totally aresed
all file
 >     except
 >      >case.struc.
 >      >Also I used all defaults as well as gmax=12, also
 >     rmt(min)*kmax=8.5, for all
 >      >calculations.
 >      >I can repeat all calculation with smaller RMT, such as 2.5,
or to
 >     check
 >      >HDLO.
 >      >I think I will start with smaller RMT. Any comments /
suggestions?
 >      >Victor
 >      >
 >      >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE
DISTANCE  MMTOT
 >      >3000 208 -77040.50516761 -.000504 0.000825   16.00318
 >      >5000 280 -77040.48748499 -.000544 0.000758   16.68523
 >      >7500 455 -77040.51668342 -.000862 0.000183   16.62547
 >      >1 540 -77040.48747210 -.000817 0.000499   16.67544
 >      >15000 840 -77040.46976815 -.000216 0.001362   16.64536
 >      >
 >      >
 >      >
 >
 >
 >
 > --
 > Professor Laurence Marks
 > "Research is to see what everybody else has seen, and to think what
 > nobody else has thought", Albert Szent-Gyorgi
 > www.numis.northwestern.edu <http://www.numis.northwestern.edu>
<http://www.numis.northwestern.edu> ;
 > Corrosion in 4D: MURI4D.numis.northwestern.edu
<http://MURI4D.numis.northwestern.edu>
 > <http://MURI4D.numis.northwestern.edu>
 > Partner of the CFW 100% program for gender equity,
 > www.cfw.org/100-percent <http://www.cfw.org/100-percent>
<http://www.cfw.org/100-percent>
 > Co-Editor, Acta Cryst A
 >
 > _

Re: [Wien] proper k-points for Nd

[Laurence Marks]

Dear Viktor,

As Fabien says, two different :MMT indicates that you have two minima. The
mixer only finds local minima, in general not the global although you can
be lucky if they are close. You probably have to look at the f density
matrix which I suspect is slightly different for the two cases. Take the
density matrix into something else and look at the eigenvectors [1] -- they
are probably different (different parity or something).

[1] I have some code "somewhere" where I added this to lapw2, and I think
it is a good general diagnostic particularly for f electrons.

On Tue, Jan 22, 2019 at 1:47 PM t...@theochem.tuwien.ac.at <
t...@theochem.tuwien.ac.at> wrote:

> Hi,
>
> Maybe the two different energies with 3 k-points correspond
> to different local minima.
>
> If not already done, then do the following:
> 1) restore the calculation with 2 k-points (restore -f ...)
> 2) execute "x kgen" to generate the mesh with 3 k-points
> 3) start the calculation (runsp_lapw -ec 0.0001 -cc 0.0001)
>
> FT
>
>
> On Tuesday 2019-01-22 20:34, Victor Zenou wrote:
>
> >Date: Tue, 22 Jan 2019 20:34:09
> >From: Victor Zenou 
> >Reply-To: A Mailing list for WIEN2k users <
> wien@zeus.theochem.tuwien.ac.at>
> >To: A Mailing list for WIEN2k users 
> >Subject: Re: [Wien] proper k-points for Nd
> >
> >Thanks Peter and Laurie for your advises. I hope we all stay friends
> after my finding :)
> >The reason I didn't progress with higher k-points (I guess it doesn't
> work backwards, higher k-points to lower) is that I actually tried that few
> times and it
> >worked (at other phase),but sometimes I got error message after the first
> cycle. In order to be systematic I tried to avoid that.
> >According to Peter's advice I tried again and got an error message (I
> can't recall if it was the same as previous) at lapw2 -up of the first
> cycle.
> >uplapw2.error file showed: " 'LAPW2" - semicore band-ranges too large,
> ghostbands ? ". I 've deleted that file and re- run SCF while unmarking the
> "iterative
> >diag" box and for some reason it worked. It worked another time, as I run
> 2 parallel sessions/cases with different k-points (Nd-SP and Nd-SP2).
> >I have good news and bad ones. The good news
> >20,000 k-points gave the same energy as 15,000 (ec 0.0001, cc 0.0001):
> 77040.469768(3) and 77040.469768(2), with same MMTOT (16.645,
> 16.647). :CHARGE
> >convergence -.000216 and -.000422, for 15000 and 2 k-points!
> >
> >Now for the troubling news:
> >30,000 k-points gave something different -77040.506092(3),
> MMTOT=16.091; CHARGE convergence -.70.
> >Running the same at different case, as I said I run 2 parallel cases
> using the same case.struc file) I got for the same 30,000
> k-points -77040.4874669(3),
> >MMTOT=16.682;  CHARGE convergence -.70.
> >It seems that using same k-points gave me two different energies. As I
> understand repeating calculation should give the same results. And if these
> two
> >calculations are the same, unless I did something stuoid,  should give
> the same result. Also, the different MMTOT may suggest something wrong with
> the spin
> >polarized calculations. Maybe I should do the k-test without spin
> polarization, as I usually do.
> >I used both to try 60,000 points, and later I will follow Laurie's and
> Peter HDLOs.
> >Victor
> >
> >
> >
> >‫בתאריך יום א׳, 20 בינו׳ 2019 ב-20:01 מאת ‪Peter Blaha‬ <‪
> pbl...@theochem.tuwien.ac.at‬>:‬
> >  I disagree with Lauries point: Eventually I want to do even an
> >  "unphysical" calculation, of course it might be you have to pay a
> price
> >  for it, because this unphysical model as eg. a spike in the DOS at
> EF.
> >  And mixer should lead to convergence, but sometimes has problems
> >  (Lauries mixer is still one of the big advantages of WIEN2k. I know
> >  other codes, which would not be able to converge a 5f system at
> all).
> >
> >  In any case, put a HDLO (5f) and increase LVNS=6 first.
> >
> >  Most importantly: why are you starting from scratch when doing the
> >  k-mesh tests. This is very error prone and in particular burns
> cpu-hours
> >  completely unnecessarily.
> >
> >  One of my main "advises" is always: do an init_lapw only ONCE !
> (except
> >  you have to change spheres).
> >
> >  You will get much better internal convergence when you continue
> using
> >  the previous calculation:
> >
> >  loop:
> >  runsp 

Re: [Wien] proper k-points for Nd

[tran]

Hi,

Maybe the two different energies with 3 k-points correspond
to different local minima.

If not already done, then do the following:
1) restore the calculation with 2 k-points (restore -f ...)
2) execute "x kgen" to generate the mesh with 3 k-points
3) start the calculation (runsp_lapw -ec 0.0001 -cc 0.0001)

FT


On Tuesday 2019-01-22 20:34, Victor Zenou wrote:


Date: Tue, 22 Jan 2019 20:34:09
From: Victor Zenou 
Reply-To: A Mailing list for WIEN2k users 
To: A Mailing list for WIEN2k users 
Subject: Re: [Wien] proper k-points for Nd

Thanks Peter and Laurie for your advises. I hope we all stay friends after my 
finding :)
The reason I didn't progress with higher k-points (I guess it doesn't work 
backwards, higher k-points to lower) is that I actually tried that few times 
and it
worked (at other phase),but sometimes I got error message after the first 
cycle. In order to be systematic I tried to avoid that.
According to Peter's advice I tried again and got an error message (I can't 
recall if it was the same as previous) at lapw2 -up of the first cycle.
uplapw2.error file showed: " 'LAPW2" - semicore band-ranges too large, ghostbands ? 
". I 've deleted that file and re- run SCF while unmarking the "iterative
diag" box and for some reason it worked. It worked another time, as I run 2 
parallel sessions/cases with different k-points (Nd-SP and Nd-SP2).
I have good news and bad ones. The good news 
20,000 k-points gave the same energy as 15,000 (ec 0.0001, cc 0.0001): 
77040.469768(3) and 77040.469768(2), with same MMTOT (16.645, 16.647). :CHARGE
convergence -.000216 and -.000422, for 15000 and 2 k-points!

Now for the troubling news:  
30,000 k-points gave something different -77040.506092(3), MMTOT=16.091; CHARGE 
convergence -.70.
Running the same at different case, as I said I run 2 parallel cases using the 
same case.struc file) I got for the same 30,000 k-points -77040.4874669(3),
MMTOT=16.682;  CHARGE convergence -.70.
It seems that using same k-points gave me two different energies. As I 
understand repeating calculation should give the same results. And if these two
calculations are the same, unless I did something stuoid,  should give the same 
result. Also, the different MMTOT may suggest something wrong with the spin
polarized calculations. Maybe I should do the k-test without spin polarization, 
as I usually do.
I used both to try 60,000 points, and later I will follow Laurie's and Peter 
HDLOs.
Victor



‫בתאריך יום א׳, 20 בינו׳ 2019 ב-20:01 מאת ‪Peter Blaha‬ 
<‪pbl...@theochem.tuwien.ac.at‬>:‬
 I disagree with Lauries point: Eventually I want to do even an
 "unphysical" calculation, of course it might be you have to pay a price
 for it, because this unphysical model as eg. a spike in the DOS at EF.
 And mixer should lead to convergence, but sometimes has problems
 (Lauries mixer is still one of the big advantages of WIEN2k. I know
 other codes, which would not be able to converge a 5f system at all).

 In any case, put a HDLO (5f) and increase LVNS=6 first.

 Most importantly: why are you starting from scratch when doing the
 k-mesh tests. This is very error prone and in particular burns cpu-hours
 completely unnecessarily.

 One of my main "advises" is always: do an init_lapw only ONCE ! (except
 you have to change spheres).

 You will get much better internal convergence when you continue using
 the previous calculation:

 loop:
 runsp 
 save XXX-k-points
 x kgen (increase the mesh always at least by a factor of 2 (maybe even 4).
 goto loop

 I'm not so much surprised about the k-mesh for a magnetic 5d-element
 calculation. I start with 1 k-points for every metallic spd-element
 and test it with 5 k. You may need 100 000 or even more. (optics for
 fcc Al is not fully converged with 1 000 000 k-points !). It does not
 cost much cpu, since you should start with a nearly converged calculation.

 Your :DIS is still quite large, try to bring it below 0.0001

 You can try TEMPS 0.002 as Laurence advised. This will most likely
 improve convergence, but most likely also reduce MMT a little bit, which
 is ok when you compare with room temp experiments, but not for 4k
 measurements ...



 Am 20.01.2019 um 17:50 schrieb Laurence Marks:
 > Sorry Fabien, I am dubious that k-points is the issue, I suspect a bad
 > model.
 >
 > Let me explain, repeating some things I have said before or are in the
 > mixer notes albeit perhaps buried.
 >
 > An "easy" assumption that many people make is that dft problems are well
 > posed, so have "simple" fixed-point solutions. In fact this is not true.
 > In reality dft problems have stacks of numerical issues which leads to

Re: [Wien] proper k-points for Nd

[Victor Zenou]

f you improve the convergence rate you will reduce the noise. Some
> > suggestions:
> >
> > 1) Use HDLO and reduce RMT
> > 2) Reduce RMT and use HDLO
> > 3) Larger LM (e.g. 8)
> > 4) Larger gmax in case.in2 (e.g. 16)
> > 5) Use TEMPS 0.0018 (room temperature)
> > 6) Peter's suggestions
> >
> > On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at
> > <mailto:t...@theochem.tuwien.ac.at>  > <mailto:t...@theochem.tuwien.ac.at>> wrote:
> >
> > Hi,
> >
> > If not too expensive, you could try more k-points (2 and 25000)
> > to see if the fluctuations persist.
> >
> > Questions: how many atoms in the unit cell? Are you optimizing the
> > position of atoms?
> >
> > F. Tran
> >
> > On Sunday 2019-01-20 17:17, Victor Zenou wrote:
> >
> >  >Date: Sun, 20 Jan 2019 17:17:55
> >  >From: Victor Zenou  > <mailto:za...@post.bgu.ac.il>>
> >  >Reply-To: A Mailing list for WIEN2k users
> >  > <mailto:wien@zeus.theochem.tuwien.ac.at>>
> >  >To: A Mailing list for WIEN2k users
> >  > <mailto:wien@zeus.theochem.tuwien.ac.at>>
> >  >Subject: Re: [Wien] proper k-points for Nd
> >  >
> >  >Dear Peter, LDM and wien2k users
> >  >I did some more calculation with energy and CHARGE convergence
> > criteria
> >  >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
> > converged to
> >  >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
> > 4*10-2 Ryd
> >  >(please see below)
> >  >I didn't check AFM yet, but this is not the point. The point is to
> get
> >  >"stable" calculation for optimal k-points.
> >  >I have to say that for each calculation I totally aresed all file
> > except
> >  >case.struc.
> >  >Also I used all defaults as well as gmax=12, also
> > rmt(min)*kmax=8.5, for all
> >  >calculations.
> >  >I can repeat all calculation with smaller RMT, such as 2.5, or to
> > check
> >  >HDLO.
> >  >I think I will start with smaller RMT. Any comments / suggestions?
> >  >Victor
> >  >
> >  >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
> >  >3000 208 -77040.50516761 -.000504 0.000825   16.00318
> >  >5000 280 -77040.48748499 -.000544 0.000758   16.68523
> >  >7500 455 -77040.51668342 -.000862 0.000183   16.62547
> >  >1 540 -77040.48747210 -.000817 0.000499   16.67544
> >  >15000 840 -77040.46976815 -.000216 0.001362   16.64536
> >  >
> >  >
> >  >
> >
> >
> >
> > --
> > Professor Laurence Marks
> > "Research is to see what everybody else has seen, and to think what
> > nobody else has thought", Albert Szent-Gyorgi
> > www.numis.northwestern.edu <http://www.numis.northwestern.edu> ;
> > Corrosion in 4D: MURI4D.numis.northwestern.edu
> > <http://MURI4D.numis.northwestern.edu>
> > Partner of the CFW 100% program for gender equity,
> > www.cfw.org/100-percent <http://www.cfw.org/100-percent>
> > Co-Editor, Acta Cryst A
> >
> > ___
> > Wien mailing list
> > Wien@zeus.theochem.tuwien.ac.at
> > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> > SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
> >
>
> --
> --
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
> Email: bl...@theochem.tuwien.ac.atWIEN2k: http://www.wien2k.at
> WWW:
>
> http://www.imc.tuwien.ac.at/tc_blaha-
>
> ___
> Wien mailing list
> Wien@zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
___
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Wien@zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
SEARCH the MAILING-LIST at:  
http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html

Re: [Wien] proper k-points for Nd

[Laurence Marks]

"Honest disagreement is often a good sign of progress" -- Mahatma Ghandi

I am not offended that Peter does not agree with my view about noise.😀

_
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu

On Sun, Jan 20, 2019, 12:01 Peter Blaha  I disagree with Lauries point: Eventually I want to do even an
> "unphysical" calculation, of course it might be you have to pay a price
> for it, because this unphysical model as eg. a spike in the DOS at EF.
> And mixer should lead to convergence, but sometimes has problems
> (Lauries mixer is still one of the big advantages of WIEN2k. I know
> other codes, which would not be able to converge a 5f system at all).
>
> In any case, put a HDLO (5f) and increase LVNS=6 first.
>
> Most importantly: why are you starting from scratch when doing the
> k-mesh tests. This is very error prone and in particular burns cpu-hours
> completely unnecessarily.
>
> One of my main "advises" is always: do an init_lapw only ONCE ! (except
> you have to change spheres).
>
> You will get much better internal convergence when you continue using
> the previous calculation:
>
> loop:
> runsp 
> save XXX-k-points
> x kgen (increase the mesh always at least by a factor of 2 (maybe even 4).
> goto loop
>
> I'm not so much surprised about the k-mesh for a magnetic 5d-element
> calculation. I start with 1 k-points for every metallic spd-element
> and test it with 5 k. You may need 100 000 or even more. (optics for
> fcc Al is not fully converged with 1 000 000 k-points !). It does not
> cost much cpu, since you should start with a nearly converged calculation.
>
> Your :DIS is still quite large, try to bring it below 0.0001
>
> You can try TEMPS 0.002 as Laurence advised. This will most likely
> improve convergence, but most likely also reduce MMT a little bit, which
> is ok when you compare with room temp experiments, but not for 4k
> measurements ...
>
>
>
> Am 20.01.2019 um 17:50 schrieb Laurence Marks:
> > Sorry Fabien, I am dubious that k-points is the issue, I suspect a bad
> > model.
> >
> > Let me explain, repeating some things I have said before or are in the
> > mixer notes albeit perhaps buried.
> >
> > An "easy" assumption that many people make is that dft problems are well
> > posed, so have "simple" fixed-point solutions. In fact this is not true.
> > In reality dft problems have stacks of numerical issues which leads to
> > "noise". You can think about this in terms of finding the minimum of
> > "F(x) = x*x + Constant*Noise(x)" where Noise(x) is some randomly
> > generated noise. The larger Constant is, the larger the deviation is
> > from x=0 of the apparent minimum. Averaging over more k-points may
> > reduce Constant, but often in my experience does relatively little.
> >
> > A symptom of noise is poor convergence -- which is clearly what is
> > occurring here.
> >
> > If you improve the convergence rate you will reduce the noise. Some
> > suggestions:
> >
> > 1) Use HDLO and reduce RMT
> > 2) Reduce RMT and use HDLO
> > 3) Larger LM (e.g. 8)
> > 4) Larger gmax in case.in2 (e.g. 16)
> > 5) Use TEMPS 0.0018 (room temperature)
> > 6) Peter's suggestions
> >
> > On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at
> > <mailto:t...@theochem.tuwien.ac.at>  > <mailto:t...@theochem.tuwien.ac.at>> wrote:
> >
> > Hi,
> >
> > If not too expensive, you could try more k-points (2 and 25000)
> > to see if the fluctuations persist.
> >
> > Questions: how many atoms in the unit cell? Are you optimizing the
> >     position of atoms?
> >
> > F. Tran
> >
> > On Sunday 2019-01-20 17:17, Victor Zenou wrote:
> >
> >  >Date: Sun, 20 Jan 2019 17:17:55
> >  >From: Victor Zenou  > <mailto:za...@post.bgu.ac.il>>
> >  >Reply-To: A Mailing list for WIEN2k users
> >  > <mailto:wien@zeus.theochem.tuwien.ac.at>>
> >  >To: A Mailing list for WIEN2k users
> >  > <mailto:wien@zeus.theochem.tuwien.ac.at>>
> >  >Subject: Re: [Wien] proper k-points for Nd
> >  >
> >  >Dear Peter, LDM and wien2k users
> >  >I did some more calculation with energy and CHARGE convergence
> > criteria
> >  >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
> > converged to
&

Re: [Wien] proper k-points for Nd

[Peter Blaha]

I disagree with Lauries point: Eventually I want to do even an 
"unphysical" calculation, of course it might be you have to pay a price 
for it, because this unphysical model as eg. a spike in the DOS at EF. 
And mixer should lead to convergence, but sometimes has problems 
(Lauries mixer is still one of the big advantages of WIEN2k. I know 
other codes, which would not be able to converge a 5f system at all).


In any case, put a HDLO (5f) and increase LVNS=6 first.

Most importantly: why are you starting from scratch when doing the 
k-mesh tests. This is very error prone and in particular burns cpu-hours 
completely unnecessarily.


One of my main "advises" is always: do an init_lapw only ONCE ! (except 
you have to change spheres).


You will get much better internal convergence when you continue using 
the previous calculation:


loop:
runsp 
save XXX-k-points
x kgen (increase the mesh always at least by a factor of 2 (maybe even 4).
goto loop

I'm not so much surprised about the k-mesh for a magnetic 5d-element 
calculation. I start with 1 k-points for every metallic spd-element 
and test it with 5 k. You may need 100 000 or even more. (optics for 
fcc Al is not fully converged with 1 000 000 k-points !). It does not 
cost much cpu, since you should start with a nearly converged calculation.


Your :DIS is still quite large, try to bring it below 0.0001

You can try TEMPS 0.002 as Laurence advised. This will most likely 
improve convergence, but most likely also reduce MMT a little bit, which 
is ok when you compare with room temp experiments, but not for 4k 
measurements ...




Am 20.01.2019 um 17:50 schrieb Laurence Marks:
Sorry Fabien, I am dubious that k-points is the issue, I suspect a bad 
model.


Let me explain, repeating some things I have said before or are in the 
mixer notes albeit perhaps buried.


An "easy" assumption that many people make is that dft problems are well 
posed, so have "simple" fixed-point solutions. In fact this is not true. 
In reality dft problems have stacks of numerical issues which leads to 
"noise". You can think about this in terms of finding the minimum of 
"F(x) = x*x + Constant*Noise(x)" where Noise(x) is some randomly 
generated noise. The larger Constant is, the larger the deviation is 
from x=0 of the apparent minimum. Averaging over more k-points may 
reduce Constant, but often in my experience does relatively little.


A symptom of noise is poor convergence -- which is clearly what is 
occurring here.


If you improve the convergence rate you will reduce the noise. Some 
suggestions:


1) Use HDLO and reduce RMT
2) Reduce RMT and use HDLO
3) Larger LM (e.g. 8)
4) Larger gmax in case.in2 (e.g. 16)
5) Use TEMPS 0.0018 (room temperature)
6) Peter's suggestions

On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at 
<mailto:t...@theochem.tuwien.ac.at> <mailto:t...@theochem.tuwien.ac.at>> wrote:


Hi,

If not too expensive, you could try more k-points (2 and 25000)
to see if the fluctuations persist.

Questions: how many atoms in the unit cell? Are you optimizing the
position of atoms?

F. Tran

On Sunday 2019-01-20 17:17, Victor Zenou wrote:

 >Date: Sun, 20 Jan 2019 17:17:55
 >From: Victor Zenou mailto:za...@post.bgu.ac.il>>
 >Reply-To: A Mailing list for WIEN2k users
mailto:wien@zeus.theochem.tuwien.ac.at>>
 >To: A Mailing list for WIEN2k users
mailto:wien@zeus.theochem.tuwien.ac.at>>
 >Subject: Re: [Wien] proper k-points for Nd
 >
 >Dear Peter, LDM and wien2k users
 >I did some more calculation with energy and CHARGE convergence
criteria
 >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
converged to
 >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
4*10-2 Ryd
 >(please see below)
 >I didn't check AFM yet, but this is not the point. The point is to get
 >"stable" calculation for optimal k-points.
 >I have to say that for each calculation I totally aresed all file
except
 >case.struc.
 >Also I used all defaults as well as gmax=12, also
rmt(min)*kmax=8.5, for all
 >calculations.
 >I can repeat all calculation with smaller RMT, such as 2.5, or to
check
 >HDLO.
 >I think I will start with smaller RMT. Any comments / suggestions?
 >Victor
 >
 >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
 >3000 208 -77040.50516761 -.000504 0.000825   16.00318
 >5000 280 -77040.48748499 -.000544 0.000758   16.68523
 >7500 455 -77040.51668342 -.000862 0.000183   16.62547
 >1 540 -77040.48747210 -.000817 0.000499   16.67544
 >15000 840 -77040.46976815 -.000216 0.001362   16.64536
 >
 >
 >



--
Professor 

Re: [Wien] proper k-points for Nd

[tran]

Ok, let's see. Besides this, f-systems are also problematic
because of multiple local minima with similar energies.

On Sunday 2019-01-20 17:50, Laurence Marks wrote:


Date: Sun, 20 Jan 2019 17:50:21
From: Laurence Marks 
Reply-To: A Mailing list for WIEN2k users 
To: A Mailing list for WIEN2k users 
Subject: Re: [Wien] proper k-points for Nd

Sorry Fabien, I am dubious that k-points is the issue, I suspect a bad
model.

Let me explain, repeating some things I have said before or are in the mixer
notes albeit perhaps buried.

An "easy" assumption that many people make is that dft problems are well
posed, so have "simple" fixed-point solutions. In fact this is not true. In
reality dft problems have stacks of numerical issues which leads to "noise".
You can think about this in terms of finding the minimum of "F(x) = x*x +
Constant*Noise(x)" where Noise(x) is some randomly generated noise. The
larger Constant is, the larger the deviation is from x=0 of the apparent
minimum. Averaging over more k-points may reduce Constant, but often in my
experience does relatively little.

A symptom of noise is poor convergence -- which is clearly what is occurring
here.

If you improve the convergence rate you will reduce the noise. Some
suggestions:

1) Use HDLO and reduce RMT
2) Reduce RMT and use HDLO
3) Larger LM (e.g. 8)
4) Larger gmax in case.in2 (e.g. 16)
5) Use TEMPS 0.0018 (room temperature)
6) Peter's suggestions

On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at
 wrote:
 Hi,

 If not too expensive, you could try more k-points (2 and
 25000)
 to see if the fluctuations persist.

 Questions: how many atoms in the unit cell? Are you optimizing
 the
 position of atoms?

 F. Tran

 On Sunday 2019-01-20 17:17, Victor Zenou wrote:

 >Date: Sun, 20 Jan 2019 17:17:55
 >From: Victor Zenou 
 >Reply-To: A Mailing list for WIEN2k users
 
 >To: A Mailing list for WIEN2k users
 
 >Subject: Re: [Wien] proper k-points for Nd
 >
 >Dear Peter, LDM and wien2k users
 >I did some more calculation with energy and CHARGE convergence
 criteria
 >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
 converged to
 >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
 4*10-2 Ryd
 >(please see below)
 >I didn't check AFM yet, but this is not the point. The point is
 to get
 >"stable" calculation for optimal k-points.
 >I have to say that for each calculation I totally aresed all
 file except
 >case.struc.
 >Also I used all defaults as well as gmax=12, also
 rmt(min)*kmax=8.5, for all
 >calculations.
 >I can repeat all calculation with smaller RMT, such as 2.5, or
 to check 
 >HDLO.
 >I think I will start with smaller RMT. Any comments /
 suggestions?
 >Victor
 >
 >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE 
 MMTOT
 >3000 208 -77040.50516761 -.000504 0.000825   16.00318
 >5000 280 -77040.48748499 -.000544 0.000758   16.68523
 >7500 455 -77040.51668342 -.000862 0.000183   16.62547
 >1 540 -77040.48747210 -.000817 0.000499   16.67544
 >15000 840 -77040.46976815 -.000216 0.001362   16.64536
 >
 >
 >



--
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu ; Corrosion in 4D:
MURI4D.numis.northwestern.eduPartner of the CFW 100% program for gender
equity, www.cfw.org/100-percent
Co-Editor, Acta Cryst A

___
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Re: [Wien] proper k-points for Nd

[Laurence Marks]

Sorry Fabien, I am dubious that k-points is the issue, I suspect a bad
model.

Let me explain, repeating some things I have said before or are in the
mixer notes albeit perhaps buried.

An "easy" assumption that many people make is that dft problems are well
posed, so have "simple" fixed-point solutions. In fact this is not true. In
reality dft problems have stacks of numerical issues which leads to
"noise". You can think about this in terms of finding the minimum of "F(x)
= x*x + Constant*Noise(x)" where Noise(x) is some randomly generated noise.
The larger Constant is, the larger the deviation is from x=0 of the
apparent minimum. Averaging over more k-points may reduce Constant, but
often in my experience does relatively little.

A symptom of noise is poor convergence -- which is clearly what is
occurring here.

If you improve the convergence rate you will reduce the noise. Some
suggestions:

1) Use HDLO and reduce RMT
2) Reduce RMT and use HDLO
3) Larger LM (e.g. 8)
4) Larger gmax in case.in2 (e.g. 16)
5) Use TEMPS 0.0018 (room temperature)
6) Peter's suggestions

On Sun, Jan 20, 2019 at 10:27 AM t...@theochem.tuwien.ac.at <
t...@theochem.tuwien.ac.at> wrote:

> Hi,
>
> If not too expensive, you could try more k-points (2 and 25000)
> to see if the fluctuations persist.
>
> Questions: how many atoms in the unit cell? Are you optimizing the
> position of atoms?
>
> F. Tran
>
> On Sunday 2019-01-20 17:17, Victor Zenou wrote:
>
> >Date: Sun, 20 Jan 2019 17:17:55
> >From: Victor Zenou 
> >Reply-To: A Mailing list for WIEN2k users <
> wien@zeus.theochem.tuwien.ac.at>
> >To: A Mailing list for WIEN2k users 
> >Subject: Re: [Wien] proper k-points for Nd
> >
> >Dear Peter, LDM and wien2k users
> >I did some more calculation with energy and CHARGE convergence criteria
> >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually converged
> to
> >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to 4*10-2 Ryd
> >(please see below)
> >I didn't check AFM yet, but this is not the point. The point is to get
> >"stable" calculation for optimal k-points.
> >I have to say that for each calculation I totally aresed all file except
> >case.struc.
> >Also I used all defaults as well as gmax=12, also rmt(min)*kmax=8.5, for
> all
> >calculations.
> >I can repeat all calculation with smaller RMT, such as 2.5, or to check
> >HDLO.
> >I think I will start with smaller RMT. Any comments / suggestions?
> >Victor
> >
> >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
> >3000 208 -77040.50516761 -.000504 0.000825   16.00318
> >5000 280 -77040.48748499 -.000544 0.000758   16.68523
> >7500 455 -77040.51668342 -.000862 0.000183   16.62547
> >1 540 -77040.48747210 -.000817 0.000499   16.67544
> >15000 840 -77040.46976815 -.000216 0.001362   16.64536
> >
> >
> >



-- 
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu ; Corrosion in 4D: MURI4D.numis.northwestern.edu
Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent
Co-Editor, Acta Cryst A
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Re: [Wien] proper k-points for Nd

[tran]

Try up to 3. Either the k-mesh is not dense enough or
the scf convergence is still not ok (why is there still a
:DIS of 0.001362 for 15000 with "-cc 0.0001"?).

The difficulty to converge with respect to k-mesh size
has nothing to do with RMT or HDLO.

On Sunday 2019-01-20 17:36, Victor Zenou wrote:


Date: Sun, 20 Jan 2019 17:36:23
From: Victor Zenou 
Reply-To: A Mailing list for WIEN2k users 
To: A Mailing list for WIEN2k users 
Subject: Re: [Wien] proper k-points for Nd

Yes, I can try 20,000 and 25,000 or even 30,000, but I never had to go for
that large number.
There are 4 atoms with fixed positions : 2a (0,0,0), 2c (1/3,2/3,1/4),  so
relaxation of atoms can't be done.
I have to mention its not at its optimal volume, which will be done later.
Victor

‫בתאריך יום א׳, 20 בינו׳ 2019 ב-18:27 מאת <‪t...@theochem.tuwien.ac.at‬>:‬
 Hi,

 If not too expensive, you could try more k-points (2 and
 25000)
 to see if the fluctuations persist.

 Questions: how many atoms in the unit cell? Are you optimizing
 the
 position of atoms?

 F. Tran

 On Sunday 2019-01-20 17:17, Victor Zenou wrote:

 >Date: Sun, 20 Jan 2019 17:17:55
 >From: Victor Zenou 
 >Reply-To: A Mailing list for WIEN2k users
 
 >To: A Mailing list for WIEN2k users
 
     >Subject: Re: [Wien] proper k-points for Nd
 >
 >Dear Peter, LDM and wien2k users
 >I did some more calculation with energy and CHARGE convergence
 criteria
 >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually
 converged to
 >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to
 4*10-2 Ryd
 >(please see below)
 >I didn't check AFM yet, but this is not the point. The point is
 to get
 >"stable" calculation for optimal k-points.
 >I have to say that for each calculation I totally aresed all
 file except
 >case.struc.
 >Also I used all defaults as well as gmax=12, also
 rmt(min)*kmax=8.5, for all
 >calculations.
 >I can repeat all calculation with smaller RMT, such as 2.5, or
 to check 
 >HDLO.
 >I think I will start with smaller RMT. Any comments /
 suggestions?
 >Victor
 >
 >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE 
 MMTOT
 >3000 208 -77040.50516761 -.000504 0.000825   16.00318
 >5000 280 -77040.48748499 -.000544 0.000758   16.68523
 >7500 455 -77040.51668342 -.000862 0.000183   16.62547
 >1 540 -77040.48747210 -.000817 0.000499   16.67544
 >15000 840 -77040.46976815 -.000216 0.001362   16.64536
 >
 >
 >___
 Wien mailing list
 Wien@zeus.theochem.tuwien.ac.at
 http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
 SEARCH the MAILING-LIST at: 
 http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html


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Re: [Wien] proper k-points for Nd

[Victor Zenou]

Yes, I can try 20,000 and 25,000 or even 30,000, but I never had to go for
that large number.
There are 4 atoms with fixed positions : 2a (0,0,0), 2c (1/3,2/3,1/4),  so
relaxation of atoms can't be done.
I have to mention its not at its optimal volume, which will be done later.
Victor

‫בתאריך יום א׳, 20 בינו׳ 2019 ב-18:27 מאת <‪t...@theochem.tuwien.ac.at‬‏>:‬

> Hi,
>
> If not too expensive, you could try more k-points (2 and 25000)
> to see if the fluctuations persist.
>
> Questions: how many atoms in the unit cell? Are you optimizing the
> position of atoms?
>
> F. Tran
>
> On Sunday 2019-01-20 17:17, Victor Zenou wrote:
>
> >Date: Sun, 20 Jan 2019 17:17:55
> >From: Victor Zenou 
> >Reply-To: A Mailing list for WIEN2k users <
> wien@zeus.theochem.tuwien.ac.at>
> >To: A Mailing list for WIEN2k users 
> >Subject: Re: [Wien] proper k-points for Nd
> >
> >Dear Peter, LDM and wien2k users
> >I did some more calculation with energy and CHARGE convergence criteria
> >equal to 10^-4 Ryd and 10^-3, respectively. The energy usually converged
> to
> >1*10-5 or even 1*10^-6. Still I get energy fluctuation up to 4*10-2 Ryd
> >(please see below)
> >I didn't check AFM yet, but this is not the point. The point is to get
> >"stable" calculation for optimal k-points.
> >I have to say that for each calculation I totally aresed all file except
> >case.struc.
> >Also I used all defaults as well as gmax=12, also rmt(min)*kmax=8.5, for
> all
> >calculations.
> >I can repeat all calculation with smaller RMT, such as 2.5, or to check
> >HDLO.
> >I think I will start with smaller RMT. Any comments / suggestions?
> >Victor
> >
> >K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
> >3000 208 -77040.50516761 -.000504 0.000825   16.00318
> >5000 280 -77040.48748499 -.000544 0.000758   16.68523
> >7500 455 -77040.51668342 -.000862 0.000183   16.62547
> >1 540 -77040.48747210 -.000817 0.000499   16.67544
> >15000 840 -77040.46976815 -.000216 0.001362   16.64536
> >
> >
> >___
> Wien mailing list
> Wien@zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
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Re: [Wien] proper k-points for Nd

[tran]

Hi,

If not too expensive, you could try more k-points (2 and 25000)
to see if the fluctuations persist.

Questions: how many atoms in the unit cell? Are you optimizing the
position of atoms?

F. Tran

On Sunday 2019-01-20 17:17, Victor Zenou wrote:


Date: Sun, 20 Jan 2019 17:17:55
From: Victor Zenou 
Reply-To: A Mailing list for WIEN2k users 
To: A Mailing list for WIEN2k users 
Subject: Re: [Wien] proper k-points for Nd

Dear Peter, LDM and wien2k users
I did some more calculation with energy and CHARGE convergence criteria
equal to 10^-4 Ryd and 10^-3, respectively. The energy usually converged to
1*10-5 or even 1*10^-6. Still I get energy fluctuation up to 4*10-2 Ryd
(please see below)
I didn't check AFM yet, but this is not the point. The point is to get
"stable" calculation for optimal k-points.
I have to say that for each calculation I totally aresed all file except
case.struc.
Also I used all defaults as well as gmax=12, also rmt(min)*kmax=8.5, for all
calculations.
I can repeat all calculation with smaller RMT, such as 2.5, or to check 
HDLO.
I think I will start with smaller RMT. Any comments / suggestions?
Victor

K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
3000 208 -77040.50516761 -.000504 0.000825   16.00318
5000 280 -77040.48748499 -.000544 0.000758   16.68523
7500 455 -77040.51668342 -.000862 0.000183   16.62547
1 540 -77040.48747210 -.000817 0.000499   16.67544
15000 840 -77040.46976815 -.000216 0.001362   16.64536


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Re: [Wien] proper k-points for Nd

[Victor Zenou]

Dear Peter, LDM and wien2k users
I did some more calculation with energy and CHARGE convergence criteria
equal to 10^-4 Ryd and 10^-3, respectively. The energy usually converged to
1*10-5 or even 1*10^-6. Still I get energy fluctuation up to 4*10-2 Ryd
(please see below)
I didn't check AFM yet, but this is not the point. The point is to get
"stable" calculation for optimal k-points.
I have to say that for each calculation I totally aresed all file except
case.struc.
Also I used all defaults as well as gmax=12, also rmt(min)*kmax=8.5, for
all calculations.
I can repeat all calculation with smaller RMT, such as 2.5, or to check
HDLO.
I think I will start with smaller RMT. Any comments / suggestions?
Victor

K-pointsIBZ E [Ryd], 10-4 CHARGE convergence CHARGE DISTANCE  MMTOT
3000 208 -77040.50516761 -.000504 0.000825   16.00318
5000 280 -77040.48748499 -.000544 0.000758   16.68523
7500 455 -77040.51668342 -.000862 0.000183   16.62547
1 540 -77040.48747210 -.000817 0.000499   16.67544
15000 840 -77040.46976815 -.000216 0.001362   16.64536

>
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Re: [Wien] proper k-points for Nd

[Victor Zenou]

Dear ciao Gerhard I assumed ferromagnetic structure. I didn't try afm. I
got MMTOT=~16, while experiments show ~3.5. So I probably should try afm. By
the way, there is a way for me to skip that Nd calculations and still get
what I basically looking for, which enthalpy of formation. But now I'm very
interested to know what went wrong, also to avoid that in the future. Victor

‫בתאריך יום ו׳, 18 בינו׳ 2019 ב-10:40 מאת ‪Fecher, Gerhard‬‏ <‪
fec...@uni-mainz.de‬‏>:‬

> Dear Viktor,
> what magnetic order are you assuming at the start ?
>
> I remember that afm with Nd1 (0,0,0) up and Nd2 (1/3,2/3,1/4) dn was
> converging but there was always a small difference in the magnetic moments
> even with FSM
>
> Ciao
> Gerhard
>
> DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
> "I think the problem, to be quite honest with you,
> is that you have never actually known what the question is."
>
> 
> Dr. Gerhard H. Fecher
> Institut of Inorganic and Analytical Chemistry
> Johannes Gutenberg - University
> 55099 Mainz
> and
> Max Planck Institute for Chemical Physics of Solids
> 01187 Dresden
> 
> Von: Wien [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von
> Laurence Marks [l-ma...@northwestern.edu]
> Gesendet: Donnerstag, 17. Januar 2019 22:57
> An: A Mailing list for WIEN2k users
> Betreff: Re: [Wien] proper k-points for Nd
>
> Dear Viktor,
>
> Let me add something about large RMTs. I have noticed in the past that, in
> general,  the gradient at the RMT calculated from both sides (x RMTCheck)
> is very similar, e.g.
>
> Atom   1 O| RMT Charge   0.489 Grad   0.690 | Step Charge  0.00136,
> 0.0 Gradient   0.2655, -0.2655 O
>
> The last two numbers should sum to almost zero. However, with very large
> RMTs they can deviate from this, particularly when the gradient is small. I
> think this leads to anomalies at the RMT. (Peter would say that the
> linearization is breaking down with an inadequate basis set, or something
> similar.) Reducing the RMTs generally avoids this.
>
> While it is true that larger RMTs are "better" in terms of speed for a
> single iteration, slightly smaller RMTs which may take longer for a single
> iteration but are more stable so require fewer iterations can be nett
> faster. Speed is not the same as stability and convergence, and often they
> oppose each other. (Think about the tradeoff with condenser aperture size:
> smaller is more coherent but more drift...)
>
> N.B., are you really sure that the Nd distances are that large?
>
> On Thu, Jan 17, 2019 at 3:31 PM Peter Blaha  <mailto:pbl...@theochem.tuwien.ac.at>> wrote:
> RMTs:  Make sure that you choose RMTs, which can be used in all
> elemental solids, but the same should also be used in your compound.
>
> Yes, you can use very large RMTs if you follow the recommendations
> during init_lapw:
> Use HDLOs for f and (as L.Marks mentioned) probably d.
> Use lvns=6 (or 8) in case.in1
>
> For a difficult system (and Nd with partially occupied 5f electrons is
> definitely a difficult systems), scf convergence can be more difficult.
> Thus, as mentioned before, use both -ec and -cc (at least 0.001;
> eventually a better cc is difficult to reach. Often you may need MORE
> than the default max of 40 scf cycles. So when runsp_lapw stops, make
> sure it does not stop beucause of the 40 it limits.
> Clearly, your energies with :dis=0.2 are wrong.
>
> For the compound but also the elements, make sure to use "consistent
> RKMAX" values.
> If you use: Al Ti Nd (2.3,2.5,2.7) and for your compound you use
> RKMAX=8, than   Al should be done with RKMAX=8, Ti with RKmax=8*2.5/2.3,
> Nd with 8*2.7/2.3
>
> Am 17.01.2019 um 21:19 schrieb Victor Zenou:
> > Dear Lauri
> > Thanks for your answer
> > I used only energy convergence criteria (10^-4). Still the charge
> > convergence was between 0.006 and 0.2 e.
> > The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed
> > to 5.4 which is much lower than 6.856. Usually large RMT is preferred
> > to make the calculations as fast as possible. I plan to check a phases
> > in Al-Ti-Nd and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
> > Victor
> >
> >
> >
> > ‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏
> > <‪l-ma...@northwestern.edu<mailto:l-ma...@northwestern.edu>  l-ma...@northwestern.edu<mailto:l-ma...@northwestern.edu>>‬‏>:‬
> >
> > With such large RMT you certainly need HDLO for Nd, perhaps both d &
> > f. I would not want to use such large RMTs.
> >
> &g

Re: [Wien] proper k-points for Nd

[Victor Zenou]

Hi LDM

The unit cell of Nd is hexagonal, space group *P63/mmc*  (#194), Pearson
Symbol: hP4 with lattice parameters: a= 3.659(3), c= 3.659(3) according to
B.J.Beaudry, P.E. Palmer, "The Lattice parameters of La, Ce, Pr, Nd, Sm, Eu
AND Yb", J. Less-Common Metals, 34 (1974) 225 - 231.

The interatomic distances are 3.628A to 3.659A. So yes, these are large
distances.

I can use smaller RMT for Nd and/or HDLOs.

Why do I need the same RMT of element when comparing different phases with
that element?

Victor



‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-23:58 מאת ‪Laurence Marks‬‏ <‪
l-ma...@northwestern.edu‬‏>:‬

> Dear Viktor,
>
> Let me add something about large RMTs. I have noticed in the past that, in
> general,  the gradient at the RMT calculated from both sides (x RMTCheck)
> is very similar, e.g.
>
> Atom   1 O| RMT Charge   0.489 Grad   0.690 | Step Charge  0.00136,
> 0.0 Gradient   0.2655, -0.2655 O
>
> The last two numbers should sum to almost zero. However, with very large
> RMTs they can deviate from this, particularly when the gradient is small. I
> think this leads to anomalies at the RMT. (Peter would say that the
> linearization is breaking down with an inadequate basis set, or something
> similar.) Reducing the RMTs generally avoids this.
>
> While it is true that larger RMTs are "better" in terms of speed for a
> single iteration, slightly smaller RMTs which may take longer for a single
> iteration but are more stable so require fewer iterations can be nett
> faster. Speed is not the same as stability and convergence, and often they
> oppose each other. (Think about the tradeoff with condenser aperture size:
> smaller is more coherent but more drift...)
>
> N.B., are you really sure that the Nd distances are that large?
>
> On Thu, Jan 17, 2019 at 3:31 PM Peter Blaha 
> wrote:
>
>> RMTs:  Make sure that you choose RMTs, which can be used in all
>> elemental solids, but the same should also be used in your compound.
>>
>> Yes, you can use very large RMTs if you follow the recommendations
>> during init_lapw:
>> Use HDLOs for f and (as L.Marks mentioned) probably d.
>> Use lvns=6 (or 8) in case.in1
>>
>> For a difficult system (and Nd with partially occupied 5f electrons is
>> definitely a difficult systems), scf convergence can be more difficult.
>> Thus, as mentioned before, use both -ec and -cc (at least 0.001;
>> eventually a better cc is difficult to reach. Often you may need MORE
>> than the default max of 40 scf cycles. So when runsp_lapw stops, make
>> sure it does not stop beucause of the 40 it limits.
>> Clearly, your energies with :dis=0.2 are wrong.
>>
>> For the compound but also the elements, make sure to use "consistent
>> RKMAX" values.
>> If you use: Al Ti Nd (2.3,2.5,2.7) and for your compound you use
>> RKMAX=8, than   Al should be done with RKMAX=8, Ti with RKmax=8*2.5/2.3,
>> Nd with 8*2.7/2.3
>>
>> Am 17.01.2019 um 21:19 schrieb Victor Zenou:
>> > Dear Lauri
>> > Thanks for your answer
>> > I used only energy convergence criteria (10^-4). Still the charge
>> > convergence was between 0.006 and 0.2 e.
>> > The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed
>> > to 5.4 which is much lower than 6.856. Usually large RMT is preferred
>> > to make the calculations as fast as possible. I plan to check a phases
>> > in Al-Ti-Nd and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
>> > Victor
>> >
>> >
>> >
>> > ‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏
>> > <‪l-ma...@northwestern.edu ‬‏>:‬
>> >
>> > With such large RMT you certainly need HDLO for Nd, perhaps both d &
>> > f. I would not want to use such large RMTs.
>> >
>> > Have you checked that the charge convergence is good?
>> >
>> > _
>> > Professor Laurence Marks
>> > "Research is to see what everybody else has seen, and to think what
>> > nobody else has thought", Albert Szent-Gyorgi
>> > http://www.numis.northwestern.edu <
>> http://www.numis.northwestern.edu>
>> >
>> > On Thu, Jan 17, 2019, 03:04 Victor Zenou > >  wrote:
>> >
>> > Hi
>> > Here is updated question:
>> >
>> > Dear Wien2k users
>> >
>> > I'm using wien2k version 17.1 installed on Ubunto 18.04.
>> >
>> > I need to calculate the enthalpy of formation of few
>> > intermetallic phases that include Nd. For that element I used
>> > RMT=2.7 a.u. and RMT*Kmax=8.5 for spin-polarization calculations
>> > via GGA-PBE. I didn't try spin-orbit coupling. Yet.
>> >
>> > The first stage is to choose proper k-points, which will give
>> > accurate results (I used 1x10^-4 Ryd for energy convergence) on
>> > one hand, but on the other hand won't be expensive in terms of
>> > computing time.
>> >
>> > I noticed that there are large energy fluctuations (1x10^-2 Ryd;
>> > which are 2 order of magnitude higher than the energy a

Re: [Wien] proper k-points for Nd

[Victor Zenou]

Thanks Peter The calculation was terminated for me when energy convergence
was achieved. As a default I used 240 instead of 40 cycles. I'm repeating
the few of these calculations with charge convergence 0.001. When I get
sense of it, I will try HDLOs as LDM suggested. For all phases including
Al, having the lowest RMT, I used RMT*Kmax=7. For Ti I used 7.5 and for Nd
I used 8.5, as 7/2.3~7.5/2.5~8.5/2.7.

Why I choose so large RMT for Nd? I just followed the recommendations
appearing in Wien2k website (How to select RMT radii): In order to make the
calculations as fast as possible, choose the radii as large as possible,
but consider possible structural changes ….

Also: "atoms with d (f) states may be 20 (30)% larger" …..

I have to mention that in the past I never use RMT larger than 2.5. But now
as I have 6-7 phases, I wanted to expedite my calculations.

Victor

‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-23:31 מאת ‪Peter Blaha‬‏ <‪
pbl...@theochem.tuwien.ac.at‬‏>:‬

> RMTs:  Make sure that you choose RMTs, which can be used in all
> elemental solids, but the same should also be used in your compound.
>
> Yes, you can use very large RMTs if you follow the recommendations
> during init_lapw:
> Use HDLOs for f and (as L.Marks mentioned) probably d.
> Use lvns=6 (or 8) in case.in1
>
> For a difficult system (and Nd with partially occupied 5f electrons is
> definitely a difficult systems), scf convergence can be more difficult.
> Thus, as mentioned before, use both -ec and -cc (at least 0.001;
> eventually a better cc is difficult to reach. Often you may need MORE
> than the default max of 40 scf cycles. So when runsp_lapw stops, make
> sure it does not stop beucause of the 40 it limits.
> Clearly, your energies with :dis=0.2 are wrong.
>
> For the compound but also the elements, make sure to use "consistent
> RKMAX" values.
> If you use: Al Ti Nd (2.3,2.5,2.7) and for your compound you use
> RKMAX=8, than   Al should be done with RKMAX=8, Ti with RKmax=8*2.5/2.3,
> Nd with 8*2.7/2.3
>
> Am 17.01.2019 um 21:19 schrieb Victor Zenou:
> > Dear Lauri
> > Thanks for your answer
> > I used only energy convergence criteria (10^-4). Still the charge
> > convergence was between 0.006 and 0.2 e.
> > The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed
> > to 5.4 which is much lower than 6.856. Usually large RMT is preferred
> > to make the calculations as fast as possible. I plan to check a phases
> > in Al-Ti-Nd and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
> > Victor
> >
> >
> >
> > ‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏
> > <‪l-ma...@northwestern.edu ‬‏>:‬
> >
> > With such large RMT you certainly need HDLO for Nd, perhaps both d &
> > f. I would not want to use such large RMTs.
> >
> > Have you checked that the charge convergence is good?
> >
> > _
> > Professor Laurence Marks
> > "Research is to see what everybody else has seen, and to think what
> > nobody else has thought", Albert Szent-Gyorgi
> > www.numis.northwestern.edu 
> >
> > On Thu, Jan 17, 2019, 03:04 Victor Zenou  >  wrote:
> >
> > Hi
> > Here is updated question:
> >
> > Dear Wien2k users
> >
> > I'm using wien2k version 17.1 installed on Ubunto 18.04.
> >
> > I need to calculate the enthalpy of formation of few
> > intermetallic phases that include Nd. For that element I used
> > RMT=2.7 a.u. and RMT*Kmax=8.5 for spin-polarization calculations
> > via GGA-PBE. I didn't try spin-orbit coupling. Yet.
> >
> > The first stage is to choose proper k-points, which will give
> > accurate results (I used 1x10^-4 Ryd for energy convergence) on
> > one hand, but on the other hand won't be expensive in terms of
> > computing time.
> >
> > I noticed that there are large energy fluctuations (1x10^-2 Ryd;
> > which are 2 order of magnitude higher than the energy accuracy
> > (defined by convergence criterion), even when I went to 15,000
> > k-points. Here is a list of energy as function of k-points:
> >
> > K-points  IBZ  E [Ryd]
> >
> >   100   8-77040.4692
> >
> >   500 38-77040.4780
> >
> > 100081-77040.5062
> >
> > 2000120  -77040.5061
> >
> > 3000208  -77040.4391
> >
> > 4000244  -77040.4699
> >
> > 5000280  -77040.4878
> >
> > 7500455  -77040.4707
> >
> > 1  540  -77040.4881
> >
> > 15000  840  -77040.4694
> >
> > I would be happy to get an idea what could have gone wrong.
> >
> > Best regards, Victor
> >
> >
> >
> > ‫בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת ‪Victor Zenou‬‏
> > <‪za...@post.bgu.ac.il ‬‏>:‬
> >
> 

Re: [Wien] proper k-points for Nd

[Victor Zenou]

Thanks LDM and FT
I'm repeating these calculations for Nd adding cc 0.001
Victor

‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-23:02 מאת <‪t...@theochem.tuwien.ac.at‬‏>:‬

> Hi,
>
> If :DIS at the end of the calculation is in the
> range 0.006-0.2, then it's huge. Do the calculations
> with "-cc 0.0001".
>
> FT
>
> On Thursday 2019-01-17 21:19, Victor Zenou wrote:
>
> >Date: Thu, 17 Jan 2019 21:19:31
> >From: Victor Zenou 
> >Reply-To: A Mailing list for WIEN2k users <
> wien@zeus.theochem.tuwien.ac.at>
> >To: A Mailing list for WIEN2k users 
> >Subject: Re: [Wien] proper k-points for Nd
> >
> >Dear Lauri
> >Thanks for your answer
> >I used only energy convergence criteria (10^-4). Still the charge
> convergence was between 0.006 and 0.2 e.
> >The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed
> to 5.4 which is much lower than 6.856. Usually large RMT is preferred
> to make the
> >calculations as fast as possible. I plan to check a phases in Al-Ti-Nd
> and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
> >Victor
> >
> >
> >
> >‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬ <‪
> l-ma...@northwestern.edu‬>:‬
> >  With such large RMT you certainly need HDLO for Nd, perhaps both d
> & f. I would not want to use such large RMTs.
> >
> >Have you checked that the charge convergence is good?
> >
> >_
> >Professor Laurence Marks
> >"Research is to see what everybody else has seen, and to think what
> nobody else has thought", Albert Szent-Gyorgi
> >www.numis.northwestern.edu
> >
> >On Thu, Jan 17, 2019, 03:04 Victor Zenou  >  Hi
> >Here is updated question:
> >
> >Dear Wien2k users
> >
> >I'm using wien2k version 17.1 installed on Ubunto 18.04.
> >
> >I need to calculate the enthalpy of formation of few intermetallic phases
> that include Nd. For that element I used RMT=2.7 a.u. and RMT*Kmax=8.5 for
> >spin-polarization calculations via GGA-PBE. I didn't try spin-orbit
> coupling. Yet.
> >
> >The first stage is to choose proper k-points, which will give accurate
> results (I used 1x10^-4 Ryd for energy convergence) on one hand, but on the
> >other hand won't be expensive in terms of computing time.
> >
> >I noticed that there are large energy fluctuations (1x10^-2 Ryd; which
> are 2 order of magnitude higher than the energy accuracy (defined by
> >convergence criterion), even when I went to 15,000 k-points. Here is a
> list of energy as function of k-points:
> >
> >K-points  IBZ  E [Ryd]
> >
> > 100   8-77040.4692
> >
> > 500 38-77040.4780
> >
> >100081-77040.5062
> >
> >2000120  -77040.5061
> >
> >3000208  -77040.4391
> >
> >4000244  -77040.4699
> >
> >5000280  -77040.4878
> >
> >7500455  -77040.4707
> >
> >1  540  -77040.4881
> >
> >15000  840  -77040.4694
> >
> >
> >
> >I would be happy to get an idea what could have gone wrong.
> >
> >Best regards, Victor
> >
> >
> >
> >‫בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת ‪Victor Zenou‬ <‪
> za...@post.bgu.ac.il‬>:‬
> >
> >  Dear Wien2k users
> >
> >  I'm using wien2k version 17.1 installed on Ubunto 18.04.
> >
> >  As a part of investigation of intermetallic phases in Al-Ti-Nd
> system, I need to calculate the enthalpy of formation of few phases in
> >  that system. For that purpose, I start calculating enthalpy (equal
> to energy at 0K) for each element and phase at their optimal relaxed
> >  state.  I used spin-polarization calculations. (GGA-PBE) As advised
> in Wien2k website I used the same RMT for each elements: 2.3, 2.5
> >  and 2.7 a.u. for Al, Ti and Nd, respectively. Also proper RMT*Kmax
> (7.5 to Ti, 8.5 to Nd and 7.0 for the rest).
> >
> >  The first stage is to choose proper k-points, which give you
> accurate results (I used 1x10^-4 Ryd for energy convergence) on one hand,
> >  but also some save computing time.
> >
> >  The calculation for all elements and phases went OK, but Nd. From
> certain k-points the energy fluctuated between 2 values (differed by
> >  1x10^-2). Attach a list of energy as function of k-points:
> >
> >  K-points  IBZ  E [Ryd]
> >
> >   100   8-77040.4692
> >
> >   500 38-77040.

Re: [Wien] proper k-points for Nd

[Fecher, Gerhard]

Dear Viktor,
what magnetic order are you assuming at the start ?

I remember that afm with Nd1 (0,0,0) up and Nd2 (1/3,2/3,1/4) dn was converging 
but there was always a small difference in the magnetic moments even with FSM

Ciao
Gerhard

DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
"I think the problem, to be quite honest with you,
is that you have never actually known what the question is."


Dr. Gerhard H. Fecher
Institut of Inorganic and Analytical Chemistry
Johannes Gutenberg - University
55099 Mainz
and
Max Planck Institute for Chemical Physics of Solids
01187 Dresden

Von: Wien [wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von Laurence 
Marks [l-ma...@northwestern.edu]
Gesendet: Donnerstag, 17. Januar 2019 22:57
An: A Mailing list for WIEN2k users
Betreff: Re: [Wien] proper k-points for Nd

Dear Viktor,

Let me add something about large RMTs. I have noticed in the past that, in 
general,  the gradient at the RMT calculated from both sides (x RMTCheck) is 
very similar, e.g.

Atom   1 O| RMT Charge   0.489 Grad   0.690 | Step Charge  0.00136, 0.0 
Gradient   0.2655, -0.2655 O

The last two numbers should sum to almost zero. However, with very large RMTs 
they can deviate from this, particularly when the gradient is small. I think 
this leads to anomalies at the RMT. (Peter would say that the linearization is 
breaking down with an inadequate basis set, or something similar.) Reducing the 
RMTs generally avoids this.

While it is true that larger RMTs are "better" in terms of speed for a single 
iteration, slightly smaller RMTs which may take longer for a single iteration 
but are more stable so require fewer iterations can be nett faster. Speed is 
not the same as stability and convergence, and often they oppose each other. 
(Think about the tradeoff with condenser aperture size: smaller is more 
coherent but more drift...)

N.B., are you really sure that the Nd distances are that large?

On Thu, Jan 17, 2019 at 3:31 PM Peter Blaha 
mailto:pbl...@theochem.tuwien.ac.at>> wrote:
RMTs:  Make sure that you choose RMTs, which can be used in all
elemental solids, but the same should also be used in your compound.

Yes, you can use very large RMTs if you follow the recommendations
during init_lapw:
Use HDLOs for f and (as L.Marks mentioned) probably d.
Use lvns=6 (or 8) in case.in1

For a difficult system (and Nd with partially occupied 5f electrons is
definitely a difficult systems), scf convergence can be more difficult.
Thus, as mentioned before, use both -ec and -cc (at least 0.001;
eventually a better cc is difficult to reach. Often you may need MORE
than the default max of 40 scf cycles. So when runsp_lapw stops, make
sure it does not stop beucause of the 40 it limits.
Clearly, your energies with :dis=0.2 are wrong.

For the compound but also the elements, make sure to use "consistent
RKMAX" values.
If you use: Al Ti Nd (2.3,2.5,2.7) and for your compound you use
RKMAX=8, than   Al should be done with RKMAX=8, Ti with RKmax=8*2.5/2.3,
Nd with 8*2.7/2.3

Am 17.01.2019 um 21:19 schrieb Victor Zenou:
> Dear Lauri
> Thanks for your answer
> I used only energy convergence criteria (10^-4). Still the charge
> convergence was between 0.006 and 0.2 e.
> The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed
> to 5.4 which is much lower than 6.856. Usually large RMT is preferred
> to make the calculations as fast as possible. I plan to check a phases
> in Al-Ti-Nd and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
> Victor
>
>
>
> ‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏
> <‪l-ma...@northwestern.edu<mailto:l-ma...@northwestern.edu> 
> <mailto:l-ma...@northwestern.edu<mailto:l-ma...@northwestern.edu>>‬‏>:‬
>
> With such large RMT you certainly need HDLO for Nd, perhaps both d &
> f. I would not want to use such large RMTs.
>
> Have you checked that the charge convergence is good?
>
> _
> Professor Laurence Marks
> "Research is to see what everybody else has seen, and to think what
> nobody else has thought", Albert Szent-Gyorgi
> http://www.numis.northwestern.edu <http://www.numis.northwestern.edu>
>
> On Thu, Jan 17, 2019, 03:04 Victor Zenou 
> mailto:za...@post.bgu.ac.il>
> <mailto:za...@post.bgu.ac.il<mailto:za...@post.bgu.ac.il>> wrote:
>
> Hi
> Here is updated question:
>
> Dear Wien2k users
>
> I'm using wien2k version 17.1 installed on Ubunto 18.04.
>
> I need to calculate the enthalpy of formation of few
> intermetallic phases that include Nd. For that element I used
> RMT=2.7 a.u. and RMT*Kmax=8.5 for spin-polarization calculations
> 

Re: [Wien] proper k-points for Nd

[Laurence Marks]

Dear Viktor,

Let me add something about large RMTs. I have noticed in the past that, in
general,  the gradient at the RMT calculated from both sides (x RMTCheck)
is very similar, e.g.

Atom   1 O| RMT Charge   0.489 Grad   0.690 | Step Charge  0.00136,
0.0 Gradient   0.2655, -0.2655 O

The last two numbers should sum to almost zero. However, with very large
RMTs they can deviate from this, particularly when the gradient is small. I
think this leads to anomalies at the RMT. (Peter would say that the
linearization is breaking down with an inadequate basis set, or something
similar.) Reducing the RMTs generally avoids this.

While it is true that larger RMTs are "better" in terms of speed for a
single iteration, slightly smaller RMTs which may take longer for a single
iteration but are more stable so require fewer iterations can be nett
faster. Speed is not the same as stability and convergence, and often they
oppose each other. (Think about the tradeoff with condenser aperture size:
smaller is more coherent but more drift...)

N.B., are you really sure that the Nd distances are that large?

On Thu, Jan 17, 2019 at 3:31 PM Peter Blaha 
wrote:

> RMTs:  Make sure that you choose RMTs, which can be used in all
> elemental solids, but the same should also be used in your compound.
>
> Yes, you can use very large RMTs if you follow the recommendations
> during init_lapw:
> Use HDLOs for f and (as L.Marks mentioned) probably d.
> Use lvns=6 (or 8) in case.in1
>
> For a difficult system (and Nd with partially occupied 5f electrons is
> definitely a difficult systems), scf convergence can be more difficult.
> Thus, as mentioned before, use both -ec and -cc (at least 0.001;
> eventually a better cc is difficult to reach. Often you may need MORE
> than the default max of 40 scf cycles. So when runsp_lapw stops, make
> sure it does not stop beucause of the 40 it limits.
> Clearly, your energies with :dis=0.2 are wrong.
>
> For the compound but also the elements, make sure to use "consistent
> RKMAX" values.
> If you use: Al Ti Nd (2.3,2.5,2.7) and for your compound you use
> RKMAX=8, than   Al should be done with RKMAX=8, Ti with RKmax=8*2.5/2.3,
> Nd with 8*2.7/2.3
>
> Am 17.01.2019 um 21:19 schrieb Victor Zenou:
> > Dear Lauri
> > Thanks for your answer
> > I used only energy convergence criteria (10^-4). Still the charge
> > convergence was between 0.006 and 0.2 e.
> > The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed
> > to 5.4 which is much lower than 6.856. Usually large RMT is preferred
> > to make the calculations as fast as possible. I plan to check a phases
> > in Al-Ti-Nd and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
> > Victor
> >
> >
> >
> > ‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏
> > <‪l-ma...@northwestern.edu ‬‏>:‬
> >
> > With such large RMT you certainly need HDLO for Nd, perhaps both d &
> > f. I would not want to use such large RMTs.
> >
> > Have you checked that the charge convergence is good?
> >
> > _
> > Professor Laurence Marks
> > "Research is to see what everybody else has seen, and to think what
> > nobody else has thought", Albert Szent-Gyorgi
> > http://www.numis.northwestern.edu  >
> >
> > On Thu, Jan 17, 2019, 03:04 Victor Zenou  >  wrote:
> >
> > Hi
> > Here is updated question:
> >
> > Dear Wien2k users
> >
> > I'm using wien2k version 17.1 installed on Ubunto 18.04.
> >
> > I need to calculate the enthalpy of formation of few
> > intermetallic phases that include Nd. For that element I used
> > RMT=2.7 a.u. and RMT*Kmax=8.5 for spin-polarization calculations
> > via GGA-PBE. I didn't try spin-orbit coupling. Yet.
> >
> > The first stage is to choose proper k-points, which will give
> > accurate results (I used 1x10^-4 Ryd for energy convergence) on
> > one hand, but on the other hand won't be expensive in terms of
> > computing time.
> >
> > I noticed that there are large energy fluctuations (1x10^-2 Ryd;
> > which are 2 order of magnitude higher than the energy accuracy
> > (defined by convergence criterion), even when I went to 15,000
> > k-points. Here is a list of energy as function of k-points:
> >
> > K-points  IBZ  E [Ryd]
> >
> >   100   8-77040.4692
> >
> >   500 38-77040.4780
> >
> > 100081-77040.5062
> >
> > 2000120  -77040.5061
> >
> > 3000208  -77040.4391
> >
> > 4000244  -77040.4699
> >
> > 5000280  -77040.4878
> >
> > 7500455  -77040.4707
> >
> > 1  540  -77040.4881
> >
> > 15000  840  -77040.4694
> >
> > I would be happy to get an idea what could have g

Re: [Wien] proper k-points for Nd

[Peter Blaha]

RMTs:  Make sure that you choose RMTs, which can be used in all 
elemental solids, but the same should also be used in your compound.


Yes, you can use very large RMTs if you follow the recommendations 
during init_lapw:

Use HDLOs for f and (as L.Marks mentioned) probably d.
Use lvns=6 (or 8) in case.in1

For a difficult system (and Nd with partially occupied 5f electrons is 
definitely a difficult systems), scf convergence can be more difficult. 
Thus, as mentioned before, use both -ec and -cc (at least 0.001; 
eventually a better cc is difficult to reach. Often you may need MORE 
than the default max of 40 scf cycles. So when runsp_lapw stops, make 
sure it does not stop beucause of the 40 it limits.

Clearly, your energies with :dis=0.2 are wrong.

For the compound but also the elements, make sure to use "consistent 
RKMAX" values.
If you use: Al Ti Nd (2.3,2.5,2.7) and for your compound you use 
RKMAX=8, than   Al should be done with RKMAX=8, Ti with RKmax=8*2.5/2.3, 
Nd with 8*2.7/2.3


Am 17.01.2019 um 21:19 schrieb Victor Zenou:

Dear Lauri
Thanks for your answer
I used only energy convergence criteria (10^-4). Still the charge 
convergence was between 0.006 and 0.2 e.
The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed 
to 5.4 which is much lower than 6.856. Usually large RMT is preferred 
to make the calculations as fast as possible. I plan to check a phases 
in Al-Ti-Nd and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.

Victor



‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏ 
<‪l-ma...@northwestern.edu ‬‏>:‬


With such large RMT you certainly need HDLO for Nd, perhaps both d &
f. I would not want to use such large RMTs.

Have you checked that the charge convergence is good?

_
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what
nobody else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu 

On Thu, Jan 17, 2019, 03:04 Victor Zenou mailto:za...@post.bgu.ac.il> wrote:

Hi
Here is updated question:

Dear Wien2k users

I'm using wien2k version 17.1 installed on Ubunto 18.04.

I need to calculate the enthalpy of formation of few
intermetallic phases that include Nd. For that element I used
RMT=2.7 a.u. and RMT*Kmax=8.5 for spin-polarization calculations
via GGA-PBE. I didn't try spin-orbit coupling. Yet.

The first stage is to choose proper k-points, which will give
accurate results (I used 1x10^-4 Ryd for energy convergence) on
one hand, but on the other hand won't be expensive in terms of
computing time.

I noticed that there are large energy fluctuations (1x10^-2 Ryd;
which are 2 order of magnitude higher than the energy accuracy
(defined by convergence criterion), even when I went to 15,000
k-points. Here is a list of energy as function of k-points:

K-points  IBZ  E [Ryd]

  100   8    -77040.4692

  500 38    -77040.4780

1000    81    -77040.5062

2000    120  -77040.5061

3000    208  -77040.4391

4000    244  -77040.4699

5000    280  -77040.4878

7500    455  -77040.4707

1  540  -77040.4881

15000  840  -77040.4694

I would be happy to get an idea what could have gone wrong.

Best regards, Victor



‫בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת ‪Victor Zenou‬‏
<‪za...@post.bgu.ac.il ‬‏>:‬

Dear Wien2k users

I'm using wien2k version 17.1 installed on Ubunto 18.04.

As a part of investigation of intermetallic phases in
Al-Ti-Nd system, I need to calculate the enthalpy of
formation of few phases in that system. For that purpose, I
start calculating enthalpy (equal to energy at 0K) for each
element and phase at their optimal relaxed state. I used
spin-polarization calculations. (GGA-PBE) As advised in
Wien2k website I used the same RMT for each elements: 2.3,
2.5 and 2.7 a.u. for Al, Ti and Nd, respectively. Also
proper RMT*Kmax (7.5 to Ti, 8.5 to Nd and 7.0 for the rest).

The first stage is to choose proper k-points, which give you
accurate results (I used 1x10^-4 Ryd for energy convergence)
on one hand, but also some save computing time.

The calculation for all elements and phases went OK, but Nd.
From certain k-points the energy fluctuated between 2 values
(differed by 1x10^-2). Attach a list of energy as function
of k-points:

K-pointsIBZ E [Ryd]

1008-77040.4692

50038-77040.4780

100081-77040.5062

Re: [Wien] proper k-points for Nd

[tran]

Hi,

If :DIS at the end of the calculation is in the
range 0.006-0.2, then it's huge. Do the calculations
with "-cc 0.0001".

FT

On Thursday 2019-01-17 21:19, Victor Zenou wrote:


Date: Thu, 17 Jan 2019 21:19:31
From: Victor Zenou 
Reply-To: A Mailing list for WIEN2k users 
To: A Mailing list for WIEN2k users 
Subject: Re: [Wien] proper k-points for Nd

Dear Lauri
Thanks for your answer
I used only energy convergence criteria (10^-4). Still the charge convergence 
was between 0.006 and 0.2 e.
The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed to 5.4 
which is much lower than 6.856. Usually large RMT is preferred to make the
calculations as fast as possible. I plan to check a phases in Al-Ti-Nd and I 
chose RMT equal to 2.3, 2.5 and 2.7 respectively.
Victor



‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬ 
<‪l-ma...@northwestern.edu‬>:‬
 With such large RMT you certainly need HDLO for Nd, perhaps both d & f. I 
would not want to use such large RMTs.

Have you checked that the charge convergence is good? 

_
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody else has 
thought", Albert Szent-Gyorgi
www.numis.northwestern.edu

On Thu, Jan 17, 2019, 03:04 Victor Zenou :‬

 Dear Wien2k users

 I'm using wien2k version 17.1 installed on Ubunto 18.04.

 As a part of investigation of intermetallic phases in Al-Ti-Nd system, I 
need to calculate the enthalpy of formation of few phases in
 that system. For that purpose, I start calculating enthalpy (equal to 
energy at 0K) for each element and phase at their optimal relaxed
 state.  I used spin-polarization calculations. (GGA-PBE) As advised in 
Wien2k website I used the same RMT for each elements: 2.3, 2.5
 and 2.7 a.u. for Al, Ti and Nd, respectively. Also proper RMT*Kmax (7.5 to 
Ti, 8.5 to Nd and 7.0 for the rest).

 The first stage is to choose proper k-points, which give you accurate 
results (I used 1x10^-4 Ryd for energy convergence) on one hand,
 but also some save computing time.

 The calculation for all elements and phases went OK, but Nd. From certain 
k-points the energy fluctuated between 2 values (differed by
 1x10^-2). Attach a list of energy as function of k-points:

 K-points  IBZ  E [Ryd]

  100   8    -77040.4692

  500 38    -77040.4780

 1000    81    -77040.5062

 2000    120  -77040.5061

 3000    208  -77040.4391

 4000    244  -77040.4699

 5000    280  -77040.4878

 7500    455  -77040.4707

 1  540  -77040.4881

 15000  840  -77040.4694

  

 I tried to get smart and did volume optimization using 4000 k-points, 
later 5000 k-points. I got strange results.

 I would be happy to get an idea what could have gone wrong.

 I didn't try spin-orbit coupling

 Best regards, Victor  

  

  

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Re: [Wien] proper k-points for Nd

[Victor Zenou]

Dear Lauri
Thanks for your answer
I used only energy convergence criteria (10^-4). Still the charge
convergence was between 0.006 and 0.2 e.
The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed to
5.4 which is much lower than 6.856. Usually large RMT is preferred to make
the calculations as fast as possible. I plan to check a phases in Al-Ti-Nd
and I chose RMT equal to 2.3, 2.5 and 2.7 respectively.
Victor



‫בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת ‪Laurence Marks‬‏ <‪
l-ma...@northwestern.edu‬‏>:‬

> With such large RMT you certainly need HDLO for Nd, perhaps both d & f. I
> would not want to use such large RMTs.
>
> Have you checked that the charge convergence is good?
>
> _
> Professor Laurence Marks
> "Research is to see what everybody else has seen, and to think what nobody
> else has thought", Albert Szent-Gyorgi
> www.numis.northwestern.edu
>
> On Thu, Jan 17, 2019, 03:04 Victor Zenou 
>> Hi
>> Here is updated question:
>>
>> Dear Wien2k users
>>
>> I'm using wien2k version 17.1 installed on Ubunto 18.04.
>>
>> I need to calculate the enthalpy of formation of few intermetallic phases
>> that include Nd. For that element I used RMT=2.7 a.u. and RMT*Kmax=8.5
>> for spin-polarization calculations via GGA-PBE. I didn't try spin-orbit
>> coupling. Yet.
>>
>> The first stage is to choose proper k-points, which will give accurate
>> results (I used 1x10^-4 Ryd for energy convergence) on one hand, but on the
>> other hand won't be expensive in terms of computing time.
>>
>> I noticed that there are large energy fluctuations (1x10^-2 Ryd; which
>> are 2 order of magnitude higher than the energy accuracy (defined by
>> convergence criterion), even when I went to 15,000 k-points. Here is a list
>> of energy as function of k-points:
>>
>> K-points  IBZ  E [Ryd]
>>
>>  100   8-77040.4692
>>
>>  500 38-77040.4780
>>
>> 100081-77040.5062
>>
>> 2000120  -77040.5061
>>
>> 3000208  -77040.4391
>>
>> 4000244  -77040.4699
>>
>> 5000280  -77040.4878
>>
>> 7500455  -77040.4707
>>
>> 1  540  -77040.4881
>>
>> 15000  840  -77040.4694
>>
>>
>>
>> I would be happy to get an idea what could have gone wrong.
>>
>> Best regards, Victor
>>
>>
>> ‫בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת ‪Victor Zenou‬‏ <‪
>> za...@post.bgu.ac.il‬‏>:‬
>>
>>> Dear Wien2k users
>>>
>>> I'm using wien2k version 17.1 installed on Ubunto 18.04.
>>>
>>> As a part of investigation of intermetallic phases in Al-Ti-Nd system, I
>>> need to calculate the enthalpy of formation of few phases in that system.
>>> For that purpose, I start calculating enthalpy (equal to energy at 0K) for
>>> each element and phase at their optimal relaxed state.  I used
>>> spin-polarization calculations. (GGA-PBE) As advised in Wien2k website I
>>> used the same RMT for each elements: 2.3, 2.5 and 2.7 a.u. for Al, Ti and
>>> Nd, respectively. Also proper RMT*Kmax (7.5 to Ti, 8.5 to Nd and 7.0 for
>>> the rest).
>>>
>>> The first stage is to choose proper k-points, which give you accurate
>>> results (I used 1x10^-4 Ryd for energy convergence) on one hand, but also
>>> some save computing time.
>>>
>>> The calculation for all elements and phases went OK, but Nd. From
>>> certain k-points the energy fluctuated between 2 values (differed by
>>> 1x10^-2). Attach a list of energy as function of k-points:
>>>
>>> K-points  IBZ  E [Ryd]
>>>
>>>  100   8-77040.4692
>>>
>>>  500 38-77040.4780
>>>
>>> 100081-77040.5062
>>>
>>> 2000120  -77040.5061
>>>
>>> 3000208  -77040.4391
>>>
>>> 4000244  -77040.4699
>>>
>>> 5000280  -77040.4878
>>>
>>> 7500455  -77040.4707
>>>
>>> 1  540  -77040.4881
>>>
>>> 15000  840  -77040.4694
>>>
>>>
>>>
>>> I tried to get smart and did volume optimization using 4000 k-points,
>>> later 5000 k-points. I got strange results.
>>>
>>> I would be happy to get an idea what could have gone wrong.
>>>
>>> I didn't try spin-orbit coupling
>>>
>>> Best regards, Victor
>>>
>>>
>>>
>>>
>>>
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Re: [Wien] proper k-points for Nd

[Laurence Marks]

With such large RMT you certainly need HDLO for Nd, perhaps both d & f. I
would not want to use such large RMTs.

Have you checked that the charge convergence is good?

_
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody
else has thought", Albert Szent-Gyorgi
www.numis.northwestern.edu

On Thu, Jan 17, 2019, 03:04 Victor Zenou  Hi
> Here is updated question:
>
> Dear Wien2k users
>
> I'm using wien2k version 17.1 installed on Ubunto 18.04.
>
> I need to calculate the enthalpy of formation of few intermetallic phases
> that include Nd. For that element I used RMT=2.7 a.u. and RMT*Kmax=8.5
> for spin-polarization calculations via GGA-PBE. I didn't try spin-orbit
> coupling. Yet.
>
> The first stage is to choose proper k-points, which will give accurate
> results (I used 1x10^-4 Ryd for energy convergence) on one hand, but on the
> other hand won't be expensive in terms of computing time.
>
> I noticed that there are large energy fluctuations (1x10^-2 Ryd; which
> are 2 order of magnitude higher than the energy accuracy (defined by
> convergence criterion), even when I went to 15,000 k-points. Here is a list
> of energy as function of k-points:
>
> K-points  IBZ  E [Ryd]
>
>  100   8-77040.4692
>
>  500 38-77040.4780
>
> 100081-77040.5062
>
> 2000120  -77040.5061
>
> 3000208  -77040.4391
>
> 4000244  -77040.4699
>
> 5000280  -77040.4878
>
> 7500455  -77040.4707
>
> 1  540  -77040.4881
>
> 15000  840  -77040.4694
>
>
>
> I would be happy to get an idea what could have gone wrong.
>
> Best regards, Victor
>
>
> ‫בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת ‪Victor Zenou‬‏ <‪
> za...@post.bgu.ac.il‬‏>:‬
>
>> Dear Wien2k users
>>
>> I'm using wien2k version 17.1 installed on Ubunto 18.04.
>>
>> As a part of investigation of intermetallic phases in Al-Ti-Nd system, I
>> need to calculate the enthalpy of formation of few phases in that system.
>> For that purpose, I start calculating enthalpy (equal to energy at 0K) for
>> each element and phase at their optimal relaxed state.  I used
>> spin-polarization calculations. (GGA-PBE) As advised in Wien2k website I
>> used the same RMT for each elements: 2.3, 2.5 and 2.7 a.u. for Al, Ti and
>> Nd, respectively. Also proper RMT*Kmax (7.5 to Ti, 8.5 to Nd and 7.0 for
>> the rest).
>>
>> The first stage is to choose proper k-points, which give you accurate
>> results (I used 1x10^-4 Ryd for energy convergence) on one hand, but also
>> some save computing time.
>>
>> The calculation for all elements and phases went OK, but Nd. From certain
>> k-points the energy fluctuated between 2 values (differed by 1x10^-2).
>> Attach a list of energy as function of k-points:
>>
>> K-points  IBZ  E [Ryd]
>>
>>  100   8-77040.4692
>>
>>  500 38-77040.4780
>>
>> 100081-77040.5062
>>
>> 2000120  -77040.5061
>>
>> 3000208  -77040.4391
>>
>> 4000244  -77040.4699
>>
>> 5000280  -77040.4878
>>
>> 7500455  -77040.4707
>>
>> 1  540  -77040.4881
>>
>> 15000  840  -77040.4694
>>
>>
>>
>> I tried to get smart and did volume optimization using 4000 k-points,
>> later 5000 k-points. I got strange results.
>>
>> I would be happy to get an idea what could have gone wrong.
>>
>> I didn't try spin-orbit coupling
>>
>> Best regards, Victor
>>
>>
>>
>>
>>
>
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Re: [Wien] proper k-points for Nd

[Victor Zenou]

Hi
Here is updated question:

Dear Wien2k users

I'm using wien2k version 17.1 installed on Ubunto 18.04.

I need to calculate the enthalpy of formation of few intermetallic phases
that include Nd. For that element I used RMT=2.7 a.u. and RMT*Kmax=8.5
for spin-polarization
calculations via GGA-PBE. I didn't try spin-orbit coupling. Yet.

The first stage is to choose proper k-points, which will give accurate
results (I used 1x10^-4 Ryd for energy convergence) on one hand, but on the
other hand won't be expensive in terms of computing time.

I noticed that there are large energy fluctuations (1x10^-2 Ryd; which are
2 order of magnitude higher than the energy accuracy (defined by
convergence criterion), even when I went to 15,000 k-points. Here is a list
of energy as function of k-points:

K-points  IBZ  E [Ryd]

 100   8-77040.4692

 500 38-77040.4780

100081-77040.5062

2000120  -77040.5061

3000208  -77040.4391

4000244  -77040.4699

5000280  -77040.4878

7500455  -77040.4707

1  540  -77040.4881

15000  840  -77040.4694



I would be happy to get an idea what could have gone wrong.

Best regards, Victor


‫בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת ‪Victor Zenou‬‏ <‪
za...@post.bgu.ac.il‬‏>:‬

> Dear Wien2k users
>
> I'm using wien2k version 17.1 installed on Ubunto 18.04.
>
> As a part of investigation of intermetallic phases in Al-Ti-Nd system, I
> need to calculate the enthalpy of formation of few phases in that system.
> For that purpose, I start calculating enthalpy (equal to energy at 0K) for
> each element and phase at their optimal relaxed state.  I used
> spin-polarization calculations. (GGA-PBE) As advised in Wien2k website I
> used the same RMT for each elements: 2.3, 2.5 and 2.7 a.u. for Al, Ti and
> Nd, respectively. Also proper RMT*Kmax (7.5 to Ti, 8.5 to Nd and 7.0 for
> the rest).
>
> The first stage is to choose proper k-points, which give you accurate
> results (I used 1x10^-4 Ryd for energy convergence) on one hand, but also
> some save computing time.
>
> The calculation for all elements and phases went OK, but Nd. From certain
> k-points the energy fluctuated between 2 values (differed by 1x10^-2).
> Attach a list of energy as function of k-points:
>
> K-points  IBZ  E [Ryd]
>
>  100   8-77040.4692
>
>  500 38-77040.4780
>
> 100081-77040.5062
>
> 2000120  -77040.5061
>
> 3000208  -77040.4391
>
> 4000244  -77040.4699
>
> 5000280  -77040.4878
>
> 7500455  -77040.4707
>
> 1  540  -77040.4881
>
> 15000  840  -77040.4694
>
>
>
> I tried to get smart and did volume optimization using 4000 k-points,
> later 5000 k-points. I got strange results.
>
> I would be happy to get an idea what could have gone wrong.
>
> I didn't try spin-orbit coupling
>
> Best regards, Victor
>
>
>
>
>
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[Wien] proper k-points for Nd

[Victor Zenou]

Dear Wien2k users

I'm using wien2k version 17.1 installed on Ubunto 18.04.

As a part of investigation of intermetallic phases in Al-Ti-Nd system, I
need to calculate the enthalpy of formation of few phases in that system.
For that purpose, I start calculating enthalpy (equal to energy at 0K) for
each element and phase at their optimal relaxed state.  I used
spin-polarization calculations. (GGA-PBE) As advised in Wien2k website I
used the same RMT for each elements: 2.3, 2.5 and 2.7 a.u. for Al, Ti and
Nd, respectively. Also proper RMT*Kmax (7.5 to Ti, 8.5 to Nd and 7.0 for
the rest).

The first stage is to choose proper k-points, which give you accurate
results (I used 1x10^-4 Ryd for energy convergence) on one hand, but also
some save computing time.

The calculation for all elements and phases went OK, but Nd. From certain
k-points the energy fluctuated between 2 values (differed by 1x10^-2).
Attach a list of energy as function of k-points:

K-points  IBZ  E [Ryd]

 100   8-77040.4692

 500 38-77040.4780

100081-77040.5062

2000120  -77040.5061

3000208  -77040.4391

4000244  -77040.4699

5000280  -77040.4878

7500455  -77040.4707

1  540  -77040.4881

15000  840  -77040.4694



I tried to get smart and did volume optimization using 4000 k-points, later
5000 k-points. I got strange results.

I would be happy to get an idea what could have gone wrong.

I didn't try spin-orbit coupling

Best regards, Victor
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