[Pw_forum] improper symmetry analysis

[YIN Kun]

Thanks a lot for explaining, Lorenzo. 

Perhaps using "right" and "wrong" is not suitable to describe problem. They 
just meant the symmetry which I intend to get or not. Follow your instructions, 
I get the "right" symmetry which I intend to. I think I know "how" to solve 
this problem now. And I have to spend more time to learn about FFT grid so as 
to totally understand "why" doing this way. 

L & P, Thank you again!
 
- Original Message - 
From: "Paolo Giannozzi" 
To: "PWSCF Forum" 
Sent: Wednesday, April 22, 2009 6:34 PM
Subject: Re: [Pw_forum] improper symmetry analysis


> Lorenzo Paulatto wrote:
> 
>> If I remember correctly symmetry is applied only on the FFT grid, the  
>> dimensions of the smooth grid should not matter.
> 
> you remeber correctly, but actuyally there is no ]strong reason for
> such choice: the part of the charge density that has to be symmetrized
> is calculated in the smooth grid
> 
>> Likely they are too small with respect to what your cutoffs requires!
> 
> one can try to reduce a little bit the fft dimensions, but success is
> not guaranteed! anyway the code should loudly complain
> 
> P.
> -- 
> Paolo Giannozzi, Democritos and University of Udine, Italy
> ___
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[Pw_forum] relax with casino pseudopotential

[Stefano Baroni]

which system? with which input data?
SB

On Apr 22, 2009, at 6:38 PM, mohaddeseh abbasnejad wrote:

>
> Dear all,
>
> Why does the stresses in the run with the converted CASINO  
> pseudopotential, using 1 1 1
> k points, have the undiagonal elements?
>
> Thanks in advance.
>
> Yours,
> Mohaddeseh
>
>
>
>
>
> ___
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> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum



---
Stefano Baroni - SISSA  &  DEMOCRITOS National Simulation Center -  
Trieste
http://stefano.baroni.me [+39] 040 3787 406 (tel) -528 (fax) /  
stefanobaroni (skype)

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[Pw_forum] inhomogenious k-points distribution

[Karoly Nemeth]

Hi,

I was wondering whether it would be possible to define sub-regions in the 
Brillouin-zone where PWSCF would calculate bands at an increased 
resolution as compared to the rest of the Brillouin zone. This might be 
useful in spectroscopy, when one wants to study direct transitions 
happening at a specific k-points region.
Thanks:

Karoly

***
Karoly Nemeth, Ph.D.
Argonne National Laboratory
9700 S. Cass Ave. Argonne, IL 60439.
Advanced Photon Source
X-Ray Science Division
Building 401, Room B4198
Tel. 630-252-5813
Fax: 630-252-3222
***

[Pw_forum] improper symmetry analysis

[Kun Yin]

Thank you for your answers, Paolo and Lorenzo.

First time to know using nr1,nr2,nr3 and nr1s,nr2s,nr3s keywords.^_^

Lorenzo wrote:
> "just make sure that the dimensions of the grids are multiple of the
> numbers of replicas in the fractional traslation."

I don't quite understand this sentence. Just try to increase and decrease 
default nr and nrs values as suggested. There are total 9 calculations, 1-3 
and 8-0 find symmetry right, 4-7 find symmetry wrong.

[kyin at geohpclab results]$ grep 'FFT grid:' *.out
temp-1.out: G cutoff =  744.8786  ( 170271 G-vectors) FFT grid: ( 
80, 80, 80)
temp-2.out: G cutoff =  722.7847  ( 162825 G-vectors) FFT grid: ( 
80, 80, 80)
temp-3.out: G cutoff =  704.6276  ( 156325 G-vectors) FFT grid: ( 
80, 80, 80)
temp-4.out: G cutoff =  689.2743  ( 151669 G-vectors) FFT grid: ( 
75, 75, 75)
temp-5.out: G cutoff =  676.0151  ( 147349 G-vectors) FFT grid: ( 
75, 75, 75)
temp-6.out: G cutoff =  664.3728  ( 143471 G-vectors) FFT grid: ( 
75, 75, 75)
temp-7.out: G cutoff =  654.0170  ( 140255 G-vectors) FFT grid: ( 
75, 75, 75)
temp-8.out: G cutoff =  644.7053  ( 136787 G-vectors) FFT grid: ( 
72, 72, 72)
temp-9.out: G cutoff =  636.2575  ( 134435 G-vectors) FFT grid: ( 
72, 72, 72)
[kyin at geohpclab results]$ grep 'smooth grid:' *.out
temp-1.out: G cutoff =  297.9514  (  43143 G-vectors)  smooth grid: ( 
50, 50, 50)
temp-2.out: G cutoff =  289.1139  (  41151 G-vectors)  smooth grid: ( 
50, 50, 50)
temp-3.out: G cutoff =  281.8510  (  39597 G-vectors)  smooth grid: ( 
48, 48, 48)
temp-4.out: G cutoff =  275.7097  (  38421 G-vectors)  smooth grid: ( 
48, 48, 48)
temp-5.out: G cutoff =  270.4060  (  37309 G-vectors)  smooth grid: ( 
48, 48, 48)
temp-6.out: G cutoff =  265.7491  (  36085 G-vectors)  smooth grid: ( 
48, 48, 48)
temp-7.out: G cutoff =  261.6068  (  35557 G-vectors)  smooth grid: ( 
45, 45, 45)
temp-8.out: G cutoff =  257.8821  (  34621 G-vectors)  smooth grid: ( 
45, 45, 45)
temp-9.out: G cutoff =  254.5030  (  34015 G-vectors)  smooth grid: ( 
45, 45, 45)

For No. 5 calculation, defulat value is 75 and 48. I set nr1=nr2=nr3=80, 
nr1s=nr2s=nr3s=50. It finds symmetry right!
when I decrease to nr1=nr2=nr3=72, nr1s=nr2s=nr3s=45. It reports error and 
crash.

 %% 
task # 1 from  fft_dlay_set  : error # 8  
inconsistent number of sticks 
%%--Kun
 YinPh.D. CandidateSchool of Earth Sciences and EngineeringNanjing 
University502 Geological Laboratory Building22 Hankou RoadNanjing 210093P.R. 
Chinaemail: kyin.cn at gmail.com- Original Message -From: "Paolo 
Giannozzi" To: "PWSCF Forum" Sent: Wednesday, April 22, 2009 3:45 PMSubject: Re: [Pw_forum] 
improper symmetry analysis> Lorenzo Paulatto wrote:>>> You should not decrease 
them from their default value, but only increasethem!>> actually the default 
should be slightly overestimated, so one can try to> decrease it a little bit>> 
P.> --> Paolo Giannozzi, Democritos and University of Udine, Italy> 
___> Pw_forum mailing list> 
Pw_forum at pwscf.org> http://www.democritos.it/mailman/listinfo/pw_forum

[Pw_forum] improper symmetry analysis

[Kun Yin]

Thank you, Paolo.

I have read 17.22 and 17.24 sections of user guide. I think the problem of 
my calculations arises from "they contain a fractional translation that is 
incompatible with the FFT grid" since they change in unit cell volume. As a 
consquence, they do have different number of  k points.

[kyin at geohpclab results]$ grep 'number of k points=' *.out
temp-1.out: number of k points=   16
temp-2.out: number of k points=   16
temp-3.out: number of k points=   16
temp-4.out: number of k points=   32
temp-5.out: number of k points=   32
temp-6.out: number of k points=   32
temp-7.out: number of k points=   32
temp-8.out: number of k points=   16
temp-9.out: number of k points=   16

 I think this missing of symmetries will not affect calculation of groud 
state energy. But if I use this scf calculation results to do phonon 
calculations, can I get correct phonon band assignment?

--
Kun Yin
Ph.D. Candidate
School of Earth Sciences and Engineering
Nanjing University
502 Geological Laboratory Building
22 Hankou Road
Nanjing 210093
P.R. China

email: kyin.cn at gmail.com
- Original Message - 
From: "Paolo Giannozzi" 
To: "PWSCF Forum" 
Sent: Wednesday, April 22, 2009 2:46 PM
Subject: Re: [Pw_forum] improper symmetry analysis


>
> On Apr 22, 2009, at 8:33 , Kun Yin wrote:
>
>> I don't know how to fix this "improper symmetry analysis" problem.
>> Can you help me?
>
> item 1.22 of the Troubleshooting section of the user guide
>
> ---
> Paolo Giannozzi, Democritos and University of Udine, Italy
>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum 

[Pw_forum] conv_thr for forces for relaxing ions

[Madhura Marathe]

 Dear Stefano,

 Thanks for the quick reply. This was really necessary to confirm since
the calculations are expensive. And I am more interested in the ground
state structure, may not use the actual value of the force for further
analysis.

 Madhura.

> In PWscf the forces are calculated  from the  Hellman-Feynman theorem
> (strictly true only at the stationary point) plus a correction that
> (approximately) accounts for the residual lack of self-consistency.  As
> such when the correction is large compared to the Hellman-Feynman term
> one should be careful.
> In your case I would say that the forces are  now probably very small
> and  therefore the structure is reliable.
> I would say that the actual (small) value for the force are probably
> correct within a few percent since the correction term is (according to
> the value quote) of the order of 10 % of the total (and hopefully is not
> completely wrong).
> Hope this helps,
> stefano de Gironcoli -SISSA and DEMOCRITOS
>
> Madhura Marathe wrote:
>>  Dear all,
>>
>>  During one of the ionic relaxation calculations, I got the error
>> message,
>> "SCF correction compared to forces is too large, reduce conv_thr". I am
>> using conv_thr = 1.0d-8 which is generally sufficient, so I increased
>> the
>> parameter upscale (from 10.0 to 100.0) in  to reduce the the
>> threshold during relaxation. This lead to the convergence till the last
>> ionic iteration which was converged to sufficient accuracy, when again
>> the
>> same error message occurred. The forces then are
>>  Total force = 0.000136 Total SCF correction = 0.16
>>  SCF correction compared to forces is too large, reduce conv_thr
>>
>>  There has been a recent discussion on the topic. From that, I gathered
>> that the subsequent relaxations after this error message are not
>> reliable.
>>  So my question is whether the forces are reliable in this last
>> iteration?
>> Or do I need to further reduce the conv_thr and re-run the whole
>> calculation?
>>
>>  Thanks for the help,
>>  Madhura.
>>
>>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>


-- 
Madhura Marathe,
PhD student, TSU,
JNCASR, Bangalore.
India.
Phone No: +91-80-22082835

[Pw_forum] GIPAW: impossible value for nrc

[Lorenzo Paulatto]

In data 22 aprile 2009 alle ore 14:32:09, Carlo Nervi  
 ha scritto:

> Dear all,
> I'm trying to use GIPAW module for NMR calculations.
> With the very helpful suggestions of Lorenzo Paulatto I generated the
> PAW Pseudopotentials of C and H, including gipaw. With these PP I
> performed geometry optimization whithin the cell (calculation='relax')
> and subsequently run the "calculation='scf'".


Sorry Carlo, I thought you had been following the bug report I'd opened on  
qe-forge, so I didn't bothered to alert you when I was able to "fix" it.

The problem is quite complicated, but the resolution is simple: you have  
to explicitly specify the  namelist when generating a pseudopotential  
with GIPAW data, otherwise if you have a "local" channel it won't be  
stored correctly in the GIPAW section of the UPF file.

Then, you have to rerun the scf calculations! Or, at least, overwrite  
manually the UPF files in the $OUTDIR/$PREFIX.save directory, because  
GIPAW takes the UPF files from there, and only from there. Whatever you've  
put in your pseudo directory is totally ignored by GIPAW (and most of the  
post-processing tools).

cheers

-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

 *** save italian brains ***
  http://saveitalianbrains.wordpress.com/

[Pw_forum] improper symmetry analysis

[Kun Yin]

Dear Users and Developers:

I met a weird phenomenon when calculating with a fcc crystal (sg. Fd-3m). I
used the same crystal structure. The only difference among the input files
is the value of parameter celldm(1). The crystal symmetries recognized by
pw.x  are not consistent. There are also some warnings like "symmetry
operation # not allowed" in the head of the output files.

Below is part of my shell script including input file:

primitive_volumes="1056.5261 1009.8683 972.0540 940.4584 913.4519 889.9579
869.2306 850.7331 834.0674"
i=0;
for v in $primitive_volumes; do
a=`echo 'scale=6; e(l('$v'*0.5)/3.0)' | bc -l`
i=`expr $i + 1`
cat > temp.in << EOF
 
calculation = 'relax'
restart_mode='from_scratch',
prefix='temp',
tprnfor = .true.
pseudo_dir = '$PSEUDO_DIR'
outdir = '$TMP_DIR'
 /
 
ibrav = 0, celldm(1)=$a,
nat = 14, ntyp = 3,
ecutwfc = 45.0, ecutrho = 450.0
 /
 
conv_thr =  1.0d-8
 /
 
ion_dynamics='bfgs'
 /
ATOMIC_SPECIES
 Mg  24.305  Mg.pw91-np-van.UPF
 Al  26.9815  Al.pw91-n-van.UPF
 O   15.9994   O.pw91-van_ak.UPF
K_POINTS automatic
6 6 6 0 0 0
CELL_PARAMETERS cubic
   1.0   1.0   0.0
   1.0  -1.0   0.0
   1.0   0.0   1.0
ATOMIC_POSITIONS crystal
Mg0.12500.87500.2500
Mg0.87500.12500.7500
Al0.50000.50000.
Al0.50000.0.5000
Al0.0.50000.
Al0.50000.50000.5000
O0.26230.73770.5246
O0.73770.26230.4754
O0.73770.71310.0246
O0.26230.28690.9754
O0.71310.73770.5246
O0.28690.26230.4754
O0.73770.26230.0246
O0.26230.73770.9754
EOF

Check symmetry operations in output files (grep 'Sym.Ops' *.out):
temp-1.out: 48 Sym.Ops. (with inversion)
temp-2.out: 48 Sym.Ops. (with inversion)
temp-3.out: 48 Sym.Ops. (with inversion)
temp-4.out: 12 Sym.Ops. (with inversion)
temp-5.out: 12 Sym.Ops. (with inversion)
temp-6.out: 12 Sym.Ops. (with inversion)
temp-7.out: 12 Sym.Ops. (with inversion)
temp-8.out: 48 Sym.Ops. (with inversion)
temp-9.out: 48 Sym.Ops. (with inversion)

I think the correct symmetry operations number should be 48 for this
crystal. I don't know how to fix this "improper symmetry analysis" problem.
Can you help me?

--
Kun Yin
Ph.D. Candidate
School of Earth Sciences and Engineering
Nanjing University
502 Geological Laboratory Building
22 Hankou Road
Nanjing 210093
P.R. China

email: kyin.cn at gmail.com

[Pw_forum] GIPAW: impossible value for nrc

[Carlo Nervi]

Dear all,
I'm trying to use GIPAW module for NMR calculations.
With the very helpful suggestions of Lorenzo Paulatto I generated the 
PAW Pseudopotentials of C and H, including gipaw. With these PP I 
performed geometry optimization whithin the cell (calculation='relax') 
and subsequently run the "calculation='scf'".

When I try to run gipaw.x module, I always get

   from init_gipaw_1 : error #1
   impossible value for nrc

The values for  rc, rs,
 nrc,nrs,nt, msh(nt) are:
0.000E+000  0.000E+000
0   0   1 745

so both nrc and nrs are zero, whereas they are required to be >=1.
I tried also to copy the original PP files into the directory .save 
created by pw.x, but with no success.

The gipaw input I used is:


 job = 'nmr'
 tmp_dir = 
'/home/nervi/calc/Barbiturico/Michele_periodico/GIPAW_Hex/'
   file_reconstruction ( 1 ) = 'H.pbe-paw-gipaw.recon'
   file_reconstruction ( 2 ) = 'C.pbe-paw-gipaw.recon'
 isolve = 0
 iverbosity = 1
 q_gipaw = 0.01
 spline_ps = .true.
 use_nmr_macroscopic_shape = .true.
prefix = 'Hex1'
/

Is there anything that I missed?
Could somebody give yto me further hints on what I have to do?
Thank you in advance,
Carlo
-- 
--
Carlo Nervi carlo.nervi at unito.it Tel:+39 011 6707507/8
Fax: +39 011 6707855   -   Dipartimento di Chimica IFM
via P. Giuria 7, 10125 Torino, Italy
http://lem.ch.unito.it/

[Pw_forum] conv_thr for forces for relaxing ions

[Madhura Marathe]

 Dear all,

 During one of the ionic relaxation calculations, I got the error message,
"SCF correction compared to forces is too large, reduce conv_thr". I am
using conv_thr = 1.0d-8 which is generally sufficient, so I increased the
parameter upscale (from 10.0 to 100.0) in  to reduce the the
threshold during relaxation. This lead to the convergence till the last
ionic iteration which was converged to sufficient accuracy, when again the
same error message occurred. The forces then are
 Total force = 0.000136 Total SCF correction = 0.16
 SCF correction compared to forces is too large, reduce conv_thr

 There has been a recent discussion on the topic. From that, I gathered
that the subsequent relaxations after this error message are not
reliable.
 So my question is whether the forces are reliable in this last iteration?
Or do I need to further reduce the conv_thr and re-run the whole
calculation?

 Thanks for the help,
 Madhura.

-- 
Madhura Marathe,
PhD student, TSU,
JNCASR, Bangalore.
India.
Phone No: +91-80-22082835

[Pw_forum] GIPAW: impossible value for nrc

[Davide Ceresoli]

Lorenzo Paulatto wrote:
> In data 22 aprile 2009 alle ore 14:32:09, Carlo Nervi  
>  ha scritto:
> 
>> Dear all,
>> I'm trying to use GIPAW module for NMR calculations.
>> With the very helpful suggestions of Lorenzo Paulatto I generated the
>> PAW Pseudopotentials of C and H, including gipaw. With these PP I
A small clairification to the Espresso community: right now,
the GIPAW code works only with norm-conserving pseudopotentials.
No ultrasoft/PAW yet.

Davide


-- 
+--+
   Davide Ceresoli 
   DMSE 13-4084
   Massachusetts Institute of Technology
   77 Massachusetts Avenue
   Cambridge, MA 02139-4307
   Phone: (617) 253-6026
   Mobile: +39-347-1001570
   Skype: dceresoli
+--+

[Pw_forum] PWCOND

[Alexander Smogunov]

The leads are semi-infinite in the scattering problem set-up
when they are connected by a scattering region.
To find the scattering states you need the generalised Bloch
states in the parts of leads (their unit cells) adjacent to the
scattering region. These you calculate from INFINITE leads taking the
unit cell ...
You can have a look at my home page (still very draft), where there are
some notes and examples in pwcond section.
Alexander.

 

? ???, 22/04/2009 ? 06:31 -0400, Manoj Srivastava ?:
> Dear Alexander, 
>  Thank you for your quick response. One follow up question on this. So,
> how do you describe your left and right leads, if they are different? If
> the leads are different then I need to do two calculations for the lead,
> one for each leads. They are semi-infinite, so periodicity in one is in +z
> direction and while in the other it is in -z direction.
> 
> Regards, 
> Manoj
> 
> 
>  On
> Wed, 22 Apr 2009, Alexander Smogunov wrote:
> 
> > Dear Manoj.
> The pwcond code was written assuming that the unit cell
> starts at z=0 and goes in positive z direction, the direction
> of transport. Quite probable that when you invert the
> cell it does not work properly... 
> Alexander
> 
> 
> ? ???, 21/04/2009 ? 23:44 -0400, Manoj Srivastava ?:
> > Dear PWSCF users, 
> >  I have a question regarding real band structure calculated from
> > PWCOND. Complex band code requires kx,ky and E as input and gives kz
> > as output. I have noticed that the answer for kz depends whether you have
> > unit cell vectors as (a1,a2,a3) or (a1,a2,-a3). I did a calculation for
> > Cu(001) with 2 atoms tetragonal unit cell, with the following input file - 
> > 
> > & control
> > calculation='scf'
> > pseudo_dir = '/home/manoj/espresso-4.0.1/pseudo',
> > outdir='./',
> > prefix='cu',
> >  /
> >  
> > ibrav = 0,
> > celldm(1)=4.7588286373854648
> > nat= 2,
> > ntyp= 1,
> > ecutwfc =150.0,
> > occupations='smearing',
> > smearing='gaussian',
> > degauss=0.02,
> > ecutrho=400
> >  /
> >  
> > conv_thr = 1.0e-8
> > mixing_beta=0.7
> >  /
> > ATOMIC_SPECIES
> >  Cu 63.55  Cu.pz-d-rrkjus.UPF
> > ATOMIC_POSITIONS
> >   Cu 0.0 0.0 0.0
> >   Cu 0.5 0.5 0.707106781
> > K_POINTS (automatic)
> > 8 8 8  1 1 1
> > CELL_PARAMETERS
> > 1.0 0.0 0.0
> > 0.0 1.0 0.0
> > 0.0 0.0 1.414213562
> > 
> > 
> > outdir='./'
> > prefixl='cu'
> > band_file ='bands.cu'
> > ikind=0
> > energy0=2.d0
> > denergy=-0.5
> > ewind=104.d0
> > epsproj=1.d-6
> >  /
> > 1
> > 0.0 0.0 1.0
> > 24
> > 
> > This gives me reasonable answer and it matches up with existing results. 
> > Now when I changed a3 to -a3, so that the unit cell now has become 
> > (a1,a2,-a3), the answer does not match up with the previous one. 
> > Just to give you one concrete example- 
> > at Fermi energy for kx,ky (0,0) for unit cell (a1,a2,a3) we get kz=-0.1571
> > while for (a1,a2,-a3) we get kz=0.07323. 
> > I understand that for two different set of unit cell vectors we should not
> > in general expect k_z to match, but this is a very special example, as it
> > is just mirror symmetry about xy plane. so shouldn't  kz in one set have
> > value -kz in other?
> > Thanks for your attention. 
> > 
> > Regards, 
> > Manoj Srivastava
> > Department of Physics 
> > University of Florida
> > Gainesville, FL  
> > 
> > 
> > ___
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
-- 
Alexander Smogunov 
Email: smogunov at sissa.it
Home page: http://people.sissa.it/~smogunov

[Pw_forum] improper symmetry analysis

[Paolo Giannozzi]

Lorenzo Paulatto wrote:

> If I remember correctly symmetry is applied only on the FFT grid, the  
> dimensions of the smooth grid should not matter.

you remeber correctly, but actuyally there is no ]strong reason for
such choice: the part of the charge density that has to be symmetrized
is calculated in the smooth grid

> Likely they are too small with respect to what your cutoffs requires!

one can try to reduce a little bit the fft dimensions, but success is
not guaranteed! anyway the code should loudly complain

P.
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] fully relativistic pseudopotential for Co

[Axel Kohlmeyer]

On Wed, 2009-04-22 at 07:21 -0700, ?lvaro Alves wrote:


> 
> Hi all. I build a fully relativistic pseudopotencial for cobalt. When
> testing it I found the following results for lattice parameters: a =
> 2.44 A, c = 4.03 A and c / a = 1.65. The experimental values are 2.51
> A, 4.07 A and 1.62.  I want to improve these results. Do you have any
> suggestions? My input is below.
> 

alvaro,

you can try sacrificing five chickens or a goat, bow five times to mecca
or pray 5 ave marias.

other than that, i'd say that you have a less than 3% overbinding for
the lattice parameter
and 1% deviation in c and and since both errors are towards the same
direction you have
an error of 2% in c/a. to the best of my knowledge, this is pretty much
of what people report 
as typical error margins for a gradient corrected functional, only that
i remember seeing
underbinding more commonly than overbinding (the latter would be more
common in LDA).

at this point, the black magic of pseudopotential generation begins. you
can twiddle with
cutoffs and electron configuration and see if this shifts the results
closer to what you want,
while not harming transferability (how transferable is this potential
anyways? did you test it?).

cheers,
   axel.

-- 
===
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
===
If you make something idiot-proof, the universe creates a better idiot.
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[Pw_forum] Fermi energy in doped material.

[Paolo Giannozzi]

Jiayu Dai wrote:

> How could we know the heavily doped semiconductor is a metal or 
> semiconductor? 
> Or, the fermi energy calculated is not appropriate in this case?

it depends on how "heavily" the semiconductor is doped. For doping in
the order of a few %, you can use a supercell and everything will work.
Realistic (i.e. order of magnitudes smaller) doping levels in
semiconductors cannot be simulated in this way. You have to resort to
phenomenological models in which the doping produces free charges
and the Fermi energy determines how many of them.

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] improper symmetry analysis

[Lorenzo Paulatto]

In data 22 aprile 2009 alle ore 10:17:02, Kun Yin  ha  
scritto:
> I don't quite understand this sentence. Just try to increase and decrease
> default nr and nrs values as suggested. There are total 9 calculations,  
> 1-3 and 8-0 find symmetry right, 4-7 find symmetry wrong.

There is no symmetry "right" and "wrong", in calculations 4-7 pw.x does  
not use certain symmetry operations because they are not compatible with  
the FFT grid, this will make the calculation a more expensive (as the  
reduced number of k-points is higher), but not wrong.

Let's do some number theory:
> temp-1.out: G cutoff =  744.8786  ( 170271 G-vectors) FFT grid:  
> ( 80, 80, 80)
> temp-2.out: G cutoff =  722.7847  ( 162825 G-vectors) FFT grid:  
> ( 80, 80, 80)
> temp-3.out: G cutoff =  704.6276  ( 156325 G-vectors) FFT grid:  
> ( 80, 80, 80)
> temp-4.out: G cutoff =  689.2743  ( 151669 G-vectors) FFT grid:  
> ( 75, 75, 75)
> temp-5.out: G cutoff =  676.0151  ( 147349 G-vectors) FFT grid:  
> ( 75, 75, 75)
> temp-6.out: G cutoff =  664.3728  ( 143471 G-vectors) FFT grid:  
> ( 75, 75, 75)
> temp-7.out: G cutoff =  654.0170  ( 140255 G-vectors) FFT grid:  
> ( 75, 75, 75)
> temp-8.out: G cutoff =  644.7053  ( 136787 G-vectors) FFT grid:  
> ( 72, 72, 72)
> temp-9.out: G cutoff =  636.2575  ( 134435 G-vectors) FFT grid:  
> ( 72, 72, 72)

80 = 2^4   * 5
75 =   3   * 5^2
72 = 2^3 * 3^2
In other words, when the size of you FFT grid is not a multiple of 2 a  
certain symmetry operation canot be represented properly. You should be  
able to guess which operation it is from your atomic positions  
configuration.

If I remember correctly symmetry is applied only on the FFT grid, the  
dimensions of the smooth grid should not matter.

> For No. 5 calculation, defulat value is 75 and 48. I set nr1=nr2=nr3=80,
> nr1s=nr2s=nr3s=50. It finds symmetry right!

As consequence of what said above. Setting nrX=80 and leaving nrXs to  
their default values should also work.

> when I decrease to nr1=nr2=nr3=72, nr1s=nr2s=nr3s=45. It reports error  
> and crash.

Likely they are too small with respect to what your cutoffs requires!

regards

-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

 *** save italian brains ***
  http://saveitalianbrains.wordpress.com/

[Pw_forum] conv_thr for forces for relaxing ions

[Stefano de Gironcoli]

In PWscf the forces are calculated  from the  Hellman-Feynman theorem 
(strictly true only at the stationary point) plus a correction that 
(approximately) accounts for the residual lack of self-consistency.  As 
such when the correction is large compared to the Hellman-Feynman term 
one should be careful.
In your case I would say that the forces are  now probably very small 
and  therefore the structure is reliable.
I would say that the actual (small) value for the force are probably 
correct within a few percent since the correction term is (according to 
the value quote) of the order of 10 % of the total (and hopefully is not 
completely wrong).
Hope this helps,
stefano de Gironcoli -SISSA and DEMOCRITOS

Madhura Marathe wrote:
>  Dear all,
>
>  During one of the ionic relaxation calculations, I got the error message,
> "SCF correction compared to forces is too large, reduce conv_thr". I am
> using conv_thr = 1.0d-8 which is generally sufficient, so I increased the
> parameter upscale (from 10.0 to 100.0) in  to reduce the the
> threshold during relaxation. This lead to the convergence till the last
> ionic iteration which was converged to sufficient accuracy, when again the
> same error message occurred. The forces then are
>  Total force = 0.000136 Total SCF correction = 0.16
>  SCF correction compared to forces is too large, reduce conv_thr
>
>  There has been a recent discussion on the topic. From that, I gathered
> that the subsequent relaxations after this error message are not
> reliable.
>  So my question is whether the forces are reliable in this last iteration?
> Or do I need to further reduce the conv_thr and re-run the whole
> calculation?
>
>  Thanks for the help,
>  Madhura.
>
>   

[Pw_forum] Fermi energy in doped material.

[Jiayu Dai]

Dear all,

As we know, the fermi energy of semiconductor can be placed anywhere in the band
gap. For intinsic semiconductor, the calculation using pw.x is in agreement with
it. But for doped semiconductor, for example, heavily doped semiconductor, the
fermi energy should shift into the conduction band or valence band(depend on the
type of doping), but the gap is always there. So, the question is: How could we
know the heavily doped semiconductor is a metal or semiconductor? Or, the fermi
energy calculated is not appropriate in this case?

Thanks a lot. 




--
Jiayu Dai
National University of Defense Technology, P R China

[Pw_forum] improper symmetry analysis

[Paolo Giannozzi]

Lorenzo Paulatto wrote:

> You should not decrease them from their default value, but only increase them!

actually the default should be slightly overestimated, so one can try to
decrease it a little bit

P.
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] improper symmetry analysis

[Lorenzo Paulatto]

22 aprile 2009 alle ore 09:33:32, Kun Yin  ha scritto:
>  I think this missing of symmetries will not affect calculation of groud
> state energy. But if I use this scf calculation results to do phonon
> calculations, can I get correct phonon band assignment?

Dear Kun Yin,
just manually specify the dimension of the FFT grid along the direction  
where the symmetry operation is lost, it is printed in output in this form:
  G cutoff =   84.7099  (  32329 G-vectors) FFT grid: ( 20, 20,216)
or, if you have, ecutrho > 4*ecutwfc in the following form:
  G cutoff =  677.6793  ( 365691 G-vectors) FFT grid: ( 54, 54,300)
  G cutoff =  338.8396  ( 129571 G-vectors)  smooth grid: ( 40, 40,216)
just make sure that the dimensions of the grids are multiple of the  
numbers of replicas in the fractional traslation.

Where they are not, you can specify them manually using the  
system-namelist keywords nr1, nr2 and nr3 for the FFT grid; and nr1s, nr2s  
and nr3s for the smooth grid. You should not decrease them from their  
default value, but only increase them!

regards


-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

 *** save italian brains ***
  http://saveitalianbrains.wordpress.com/

[Pw_forum] improper symmetry analysis

[Paolo Giannozzi]

Kun Yin wrote:

> "they contain a fractional translation that is incompatible with the FFT grid"

you can force the FFT grid to values that are compatible with fractional
translations, if you really need to

>  I think this missing of symmetries will not affect calculation of groud 
> state energy. 

it doesn't

> But if I use this scf calculation results to do phonon 
> calculations, can I get correct phonon band assignment?

you get a phonon band assignment that is be correct for
the symmetry the code has found

Paolo
-- 
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] relax with casino pseudopotential

[mohaddeseh abbasnejad]

 Dear all,

Why does the stresses in the run with the converted CASINO
pseudopotential, using 1 1 1
k points, have the undiagonal elements?

Thanks in advance.

Yours,
Mohaddeseh
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[Pw_forum] PWCOND

[Alexander Smogunov]

Dear Manoj.
The pwcond code was written assuming that the unit cell
starts at z=0 and goes in positive z direction, the direction
of transport. Quite probable that when you invert the
cell it does not work properly... 
Alexander


? ???, 21/04/2009 ? 23:44 -0400, Manoj Srivastava ?:
> Dear PWSCF users, 
>  I have a question regarding real band structure calculated from
> PWCOND. Complex band code requires kx,ky and E as input and gives kz
> as output. I have noticed that the answer for kz depends whether you have
> unit cell vectors as (a1,a2,a3) or (a1,a2,-a3). I did a calculation for
> Cu(001) with 2 atoms tetragonal unit cell, with the following input file - 
> 
> & control
> calculation='scf'
> pseudo_dir = '/home/manoj/espresso-4.0.1/pseudo',
> outdir='./',
> prefix='cu',
>  /
>  
> ibrav = 0,
> celldm(1)=4.7588286373854648
> nat= 2,
> ntyp= 1,
> ecutwfc =150.0,
> occupations='smearing',
> smearing='gaussian',
> degauss=0.02,
> ecutrho=400
>  /
>  
> conv_thr = 1.0e-8
> mixing_beta=0.7
>  /
> ATOMIC_SPECIES
>  Cu 63.55  Cu.pz-d-rrkjus.UPF
> ATOMIC_POSITIONS
>   Cu 0.0 0.0 0.0
>   Cu 0.5 0.5 0.707106781
> K_POINTS (automatic)
> 8 8 8  1 1 1
> CELL_PARAMETERS
> 1.0 0.0 0.0
> 0.0 1.0 0.0
> 0.0 0.0 1.414213562
> 
> 
> outdir='./'
> prefixl='cu'
> band_file ='bands.cu'
> ikind=0
> energy0=2.d0
> denergy=-0.5
> ewind=104.d0
> epsproj=1.d-6
>  /
> 1
> 0.0 0.0 1.0
> 24
> 
> This gives me reasonable answer and it matches up with existing results. 
> Now when I changed a3 to -a3, so that the unit cell now has become 
> (a1,a2,-a3), the answer does not match up with the previous one. 
> Just to give you one concrete example- 
> at Fermi energy for kx,ky (0,0) for unit cell (a1,a2,a3) we get kz=-0.1571
> while for (a1,a2,-a3) we get kz=0.07323. 
> I understand that for two different set of unit cell vectors we should not
> in general expect k_z to match, but this is a very special example, as it
> is just mirror symmetry about xy plane. so shouldn't  kz in one set have
> value -kz in other?
> Thanks for your attention. 
> 
> Regards, 
> Manoj Srivastava
> Department of Physics 
> University of Florida
> Gainesville, FL  
> 
> 
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
-- 
Alexander Smogunov 
Email: smogunov at sissa.it
Home page: http://people.sissa.it/~smogunov

[Pw_forum] improper symmetry analysis

[Paolo Giannozzi]

On Apr 22, 2009, at 8:33 , Kun Yin wrote:

> I don't know how to fix this "improper symmetry analysis" problem.
> Can you help me?

item 1.22 of the Troubleshooting section of the user guide

---
Paolo Giannozzi, Democritos and University of Udine, Italy

[Pw_forum] fully relativistic pseudopotential for Co

[Álvaro Alves]

Hi all. I build a fully relativistic pseudopotencial for cobalt. When
testing it I found the following results for lattice parameters: a =
2.44 A, c = 4.03 A and c / a = 1.65. The experimental values are 2.51 A, 4.07
A and 1.62.? I want to improve these results.
Do you have any suggestions? My input is below.

?
??? title='Co',
??? prefix='Co-rel'
??? zed=27.,
??? rel=2,
??? rlderiv=2.50,
??? eminld=-4.0,
??? emaxld=4.0
??? deld=0.02,
??? nld=3,
??? config='[Ar] 3d7.0 4s2.0 4p0.0',
??? iswitch=3,
??? dft='PBE'
?/
?
?? lloc=0,
?? pseudotype=3,
?? file_pseudopw='Co.rel-pbe.rrkjus.UPF',
?? nlcc=.true.,
?? rcore=1.2,
?? author='ASA',
?/
7
4P? 2? 1? 0.00 -0.10? 2.40? 2.40? 0.5
4P? 2? 1? 0.00 -0.10? 2.40? 2.40? 1.5
3D? 3? 2? 4.00? 0.00? 1.50? 2.10? 1.5
3D? 3? 2? 0.00 -0.30? 1.50? 2.10? 1.5
3D? 3? 2? 3.00? 0.00? 1.50? 2.10? 2.5
3D? 3? 2? 0.00 -0.30? 1.50? 2.10? 2.5
4S? 1? 0? 2.00? 0.00? 2.20? 2.20? 0.5

??? Regards, Alvaro



  Veja quais s?o os assuntos do momento no Yahoo! +Buscados
http://br.maisbuscados.yahoo.com
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[Pw_forum] PWCOND

[Manoj Srivastava]

Dear Alexander, 
 Thank you for your quick response. One follow up question on this. So,
how do you describe your left and right leads, if they are different? If
the leads are different then I need to do two calculations for the lead,
one for each leads. They are semi-infinite, so periodicity in one is in +z
direction and while in the other it is in -z direction.

Regards, 
Manoj


 On
Wed, 22 Apr 2009, Alexander Smogunov wrote:

> Dear Manoj.
The pwcond code was written assuming that the unit cell
starts at z=0 and goes in positive z direction, the direction
of transport. Quite probable that when you invert the
cell it does not work properly... 
Alexander


?? ??, 21/04/2009 ?? 23:44 -0400, Manoj Srivastava ??:
> Dear PWSCF users, 
>  I have a question regarding real band structure calculated from
> PWCOND. Complex band code requires kx,ky and E as input and gives kz
> as output. I have noticed that the answer for kz depends whether you have
> unit cell vectors as (a1,a2,a3) or (a1,a2,-a3). I did a calculation for
> Cu(001) with 2 atoms tetragonal unit cell, with the following input file - 
> 
> & control
> calculation='scf'
> pseudo_dir = '/home/manoj/espresso-4.0.1/pseudo',
> outdir='./',
> prefix='cu',
>  /
>  
> ibrav = 0,
> celldm(1)=4.7588286373854648
> nat= 2,
> ntyp= 1,
> ecutwfc =150.0,
> occupations='smearing',
> smearing='gaussian',
> degauss=0.02,
> ecutrho=400
>  /
>  
> conv_thr = 1.0e-8
> mixing_beta=0.7
>  /
> ATOMIC_SPECIES
>  Cu 63.55  Cu.pz-d-rrkjus.UPF
> ATOMIC_POSITIONS
>   Cu 0.0 0.0 0.0
>   Cu 0.5 0.5 0.707106781
> K_POINTS (automatic)
> 8 8 8  1 1 1
> CELL_PARAMETERS
> 1.0 0.0 0.0
> 0.0 1.0 0.0
> 0.0 0.0 1.414213562
> 
> 
> outdir='./'
> prefixl='cu'
> band_file ='bands.cu'
> ikind=0
> energy0=2.d0
> denergy=-0.5
> ewind=104.d0
> epsproj=1.d-6
>  /
> 1
> 0.0 0.0 1.0
> 24
> 
> This gives me reasonable answer and it matches up with existing results. 
> Now when I changed a3 to -a3, so that the unit cell now has become 
> (a1,a2,-a3), the answer does not match up with the previous one. 
> Just to give you one concrete example- 
> at Fermi energy for kx,ky (0,0) for unit cell (a1,a2,a3) we get kz=-0.1571
> while for (a1,a2,-a3) we get kz=0.07323. 
> I understand that for two different set of unit cell vectors we should not
> in general expect k_z to match, but this is a very special example, as it
> is just mirror symmetry about xy plane. so shouldn't  kz in one set have
> value -kz in other?
> Thanks for your attention. 
> 
> Regards, 
> Manoj Srivastava
> Department of Physics 
> University of Florida
> Gainesville, FL  
> 
> 
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
-- 
Alexander Smogunov 
Email: smogunov at sissa.it
Home page: http://people.sissa.it/~smogunov


___
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum

[Pw_forum] Work function of Carbon nanotube

[loc duong ding]

Dear all,

I try to calculate the work function of CNT. I follow all steps in the?work 
function example and no error in the calculation steps. I compare my result 
with?some papers and I see my results is smaller?and the?dependence of work 
function?in diameter is inverted. My results is 4.2, 3.8, 3.6 eV for (4,4), 
(5,5) and (6,6) tube. It looks strange. 
?
This?is my?input file:

input_pw


? calculation = 'scf',
? prefix='CNT0404',
? restart_mode = 'restart',
? pseudo_dir ='./',
? outdir='./'
? tstress = .true. ,
? tprnfor = .true. ,
? nstep =? 100? ,
? etot_conv_thr = 1.0E-4 ,
? forc_conv_thr = 1.0D-3 ,
? dt = 20 ,
/

? ibrav= 0,? celldm(1) = 47.259, nat = 16, ntyp = 1, nspin=1,
? ecutwfc =35, ecutrho = 210, occupations='smearing', degauss=0.0001,
? starting_magnetization(1) = 0.0,
? starting_magnetization(2) = 0.3,
? starting_magnetization(3) = 0.5??? 
/

??? startingwfc = 'atomic'
??? mixing_mode = 'plain'
??? mixing_beta = 0.6
??? conv_thr = 1.0e-6
??? electron_maxstep= 150
/

??? upscale = 15
/

?? cell_dynamics = 'bfgs' ,
?? press = 0.00 ,
?? wmass =? 0.0015? ,
/
ATOMIC_SPECIES
?C? 12.011? C.pbe-rrkjus.UPF
ATOMIC_POSITIONS {angstrom}
C??? 6.553412225?? 2.494247153?? 0.724930481
C??? 6.384209537?? 3.189335516?? 1.955034374
C??? 4.921037485?? 4.725404700?? 0.724938769
C??? 5.532498571?? 4.353613294?? 1.955042803
C??? 1.264191320?? 3.317569203?? 0.724981489
C??? 3.495616015?? 4.948134701?? 0.724939100
C??? 2.800526187?? 4.779818582?? 1.955052266
C??? 1.043153150?? 1.891599899?? 0.724952105
C??? 1.212815843?? 1.196984732?? 1.955055225
C??? 1.636733754?? 3.927573140?? 1.955082857
C??? 2.673787862? -0.341212987?? 0.724950680
C??? 2.063329729?? 0.030888435?? 1.955053025
C??? 6.331514885?? 1.068488114?? 0.724935334
C??? 4.099852762? -0.563295810?? 0.724948544
C??? 4.794456495? -0.394248320?? 1.955057038
C??? 5.959864180?? 0.457099648?? 1.955045909
K_POINTS {automatic}
1 1 9 0 0 0
CELL_PARAMETERS
?1.0?? 0.0?? 0.0
?0.0?? 1.0?? 0.0
?0.0?? 0.0?? 0.09838 

input_pp


?prefix='CNT0404' 
? outdir='./'
? plot_num= 1
? filplot='CNT0404' 
/

? iflag=3,
? output_format=3
? fileout='CNT0404.total.potential.xsf'
/ 


input_average

1?? 
CNT0404 
1?
500?
1?
2


Could you please give me some sugestions to adjust the calculations? 
What?factors should I change??
I great appreciate for your help.

Best regards,---
Loc Duong Dinh
Ms-Ph.D Student
Sungkyunkwan Advanced Institute of Nanotechnology,
Sungkyunkwan University,
Suwon, 440-746, Korea 
Email: mambom1902 at yahoo.com 


  

[Pw_forum] question for phonon calculation

[潘登]

Dear All Users,

I was going to calculating phonon frequency of MgB2 at Gamma point.But I got
the minus value at the lowest three branch.

 q = (0.0   0.0   0.0 )

 **
 omega( 1) =  -1.333147 [THz] = -44.469304 [cm-1]
 omega( 2) =  -1.333147 [THz] = -44.469304 [cm-1]
 omega( 3) =  -1.003834 [THz] = -33.484515 [cm-1]
 omega( 4) =   9.706117 [THz] = 323.763351 [cm-1]
 omega( 5) =   9.706117 [THz] = 323.763351 [cm-1]
 omega( 6) =  11.666010 [THz] = 389.138778 [cm-1]
 omega( 7) =  15.807885 [THz] = 527.297796 [cm-1]
 omega( 8) =  15.807885 [THz] = 527.297796 [cm-1]
 omega( 9) =  20.623897 [THz] = 687.943739 [cm-1]
 **

I had already relax the lattice.And below is my inputs for scf and phonon
calculation.Any suggest and comments on how to avoid the minus values was
appreciated.

scf.in
 
 calculation = 'scf'
 restart_mode='from_scratch'
 prefix='MgB2',
 pseudo_dir = '//Quantum-Espresso/espresso-4.0.3/pseudo/',
 outdir='/tmp/'
 /
 
 ibrav=4,
 celldm(1)=5.8398,
 celldm(3)=1.1420,
 nat=3,
 ntyp=2,
 ecutwfc = 45.0,
 ecutrho = 450.0,
 occupations= 'smearing',
 degauss= 0.03,
 smearing= 'cold',
 /
 
 mixing_beta = 0.7
 conv_thr =  1.0d-12
 /
ATOMIC_SPECIES
 Mg 24.3 Mg.pw91-np-van.UPF
 B  10.8 B.pw91-n-van.UPF
ATOMIC_POSITIONS
Mg00   0
B 00.57735 0.571
B 0.5  0.28868 0.571
K_POINTS {automatic}
 32 32 32 0 0 0

ph.in

 MgB2

  amass(1)= 24.3,
  amass(2)= 10.8,
  prefix='MgB2'
  tr2_ph=1.0d-25,
  alpha_mix(1)=0.5,
  iverbosity=1,
  outdir='//tmp/',
 /
0 0 0

I also wonder how to apply 'asr' to my calculation.I could not find any
option for ph.x.

Have a nice day!

Deng Pan
Nanjing University
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[Pw_forum] force in sawlike potential

[Aihua Zhang]

Dear Paulatto,

I compared the source codes under PW directory between 4.0.4 and 4.0.5. I
only found a minor relevant change in compute_dip.f90. I don't think this
change will affect the force.

Best regards

zah

On Tue, Apr 21, 2009 at 10:21 PM, Lorenzo Paulatto wrote:

> In data 21 aprile 2009 alle ore 15:55:29, Aihua Zhang 
> ha scritto:
> > I had expected the force exerted on nucleus by the field  would
> > cancel the force on ion due to change in electron charge density, so the
> > total force should vanish since the system is neutral. I also varied the
> > cutoff energy, but failed to see a convergence behavior as shown below.
> > Could anyone give me a clue? Thank you!
>
> dear Aihua Zhang,
> that part of the code has been "fixed" more than once recently, hence the
> answer depends on the exact version of QE you are using.
>
> regards
>
>
> --
> Creato con il rivoluzionario client e-mail di Opera:
> http://www.opera.com/mail/
> ___
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[Pw_forum] PWCOND

[Manoj Srivastava]

Dear PWSCF users, 
 I have a question regarding real band structure calculated from
PWCOND. Complex band code requires kx,ky and E as input and gives kz
as output. I have noticed that the answer for kz depends whether you have
unit cell vectors as (a1,a2,a3) or (a1,a2,-a3). I did a calculation for
Cu(001) with 2 atoms tetragonal unit cell, with the following input file - 

& control
calculation='scf'
pseudo_dir = '/home/manoj/espresso-4.0.1/pseudo',
outdir='./',
prefix='cu',
 /
 
ibrav = 0,
celldm(1)=4.7588286373854648
nat= 2,
ntyp= 1,
ecutwfc =150.0,
occupations='smearing',
smearing='gaussian',
degauss=0.02,
ecutrho=400
 /
 
conv_thr = 1.0e-8
mixing_beta=0.7
 /
ATOMIC_SPECIES
 Cu 63.55  Cu.pz-d-rrkjus.UPF
ATOMIC_POSITIONS
  Cu 0.0 0.0 0.0
  Cu 0.5 0.5 0.707106781
K_POINTS (automatic)
8 8 8  1 1 1
CELL_PARAMETERS
1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.414213562


outdir='./'
prefixl='cu'
band_file ='bands.cu'
ikind=0
energy0=2.d0
denergy=-0.5
ewind=104.d0
epsproj=1.d-6
 /
1
0.0 0.0 1.0
24

This gives me reasonable answer and it matches up with existing results. 
Now when I changed a3 to -a3, so that the unit cell now has become 
(a1,a2,-a3), the answer does not match up with the previous one. 
Just to give you one concrete example- 
at Fermi energy for kx,ky (0,0) for unit cell (a1,a2,a3) we get kz=-0.1571
while for (a1,a2,-a3) we get kz=0.07323. 
I understand that for two different set of unit cell vectors we should not
in general expect k_z to match, but this is a very special example, as it
is just mirror symmetry about xy plane. so shouldn't  kz in one set have
value -kz in other?
Thanks for your attention. 

Regards, 
Manoj Srivastava
Department of Physics 
University of Florida
Gainesville, FL