[Pw_forum] Bulk modulus calculation
Thanks Dr. Sanjeev for the useful link On Thu, Mar 6, 2014 at 10:28 AM, Sanjeev Gupta wrote: > Hi > > For bulk modulus, energy Vs lattice const., is always welcome. > Otherway, there are lot of discussions on PWSCF forum, as one of by Prof. > Eduardo Menendez. > > > > http://exciting.wdfiles.com/local--files/lithium-energy-vs-strain-calculations/elastic-paper.pdf > and http://exciting-code.org/elastic > > download it take espresso i/o files. > > enjoy the day! > > bests > sanjeev > > > On Thu, Mar 6, 2014 at 9:32 AM, vicky singh wrote: > >> Dear QE users >>I am calculating the bulk modulus using the ev.x executable. The bulk >> modulus obtained is extremely sensitive to the number of data i use in the >> lattice parameter vs energy table. if i use three values a-x, a, a+x, where >> a is the equilibrium lattice parameter and x is 0.01 or 0.02 bohr the value >> of bulk modulus is very high as compared to i use 5 or 10 data. Bulk >> modulus is the double derivative if energy w.r.t. equilibrium lattice >> parameter. >>What should be the best method to obtain the bulk modulus of the >> system. Also if you can provide any tutorial or help to calculate other >> elastic constant it will be extremely helpful. >> >> Vicky Singh >> RA, Bangalore >> >> ___ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > > -- > With Best Regards, > > > Dr. Sanjeev Kumar Gupta > Fulbright Post-Doctoral Scholar > Dept. of Physics > Michigan Technological University > 1400 Townsend Drive, Houghton > MI 49931, USA > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140308/2bea2011/attachment.html
[Pw_forum] Bulk modulus calculation
Hi For bulk modulus, energy Vs lattice const., is always welcome. Otherway, there are lot of discussions on PWSCF forum, as one of by Prof. Eduardo Menendez. http://exciting.wdfiles.com/local--files/lithium-energy-vs-strain-calculations/elastic-paper.pdf and http://exciting-code.org/elastic download it take espresso i/o files. enjoy the day! bests sanjeev On Thu, Mar 6, 2014 at 9:32 AM, vicky singh wrote: > Dear QE users >I am calculating the bulk modulus using the ev.x executable. The bulk > modulus obtained is extremely sensitive to the number of data i use in the > lattice parameter vs energy table. if i use three values a-x, a, a+x, where > a is the equilibrium lattice parameter and x is 0.01 or 0.02 bohr the value > of bulk modulus is very high as compared to i use 5 or 10 data. Bulk > modulus is the double derivative if energy w.r.t. equilibrium lattice > parameter. >What should be the best method to obtain the bulk modulus of the > system. Also if you can provide any tutorial or help to calculate other > elastic constant it will be extremely helpful. > > Vicky Singh > RA, Bangalore > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- With Best Regards, Dr. Sanjeev Kumar Gupta Fulbright Post-Doctoral Scholar Dept. of Physics Michigan Technological University 1400 Townsend Drive, Houghton MI 49931, USA -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140306/78e2b5c1/attachment.html
[Pw_forum] Bulk modulus calculation
Dear QE users I am calculating the bulk modulus using the ev.x executable. The bulk modulus obtained is extremely sensitive to the number of data i use in the lattice parameter vs energy table. if i use three values a-x, a, a+x, where a is the equilibrium lattice parameter and x is 0.01 or 0.02 bohr the value of bulk modulus is very high as compared to i use 5 or 10 data. Bulk modulus is the double derivative if energy w.r.t. equilibrium lattice parameter. What should be the best method to obtain the bulk modulus of the system. Also if you can provide any tutorial or help to calculate other elastic constant it will be extremely helpful. Vicky Singh RA, Bangalore -- next part -- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140306/725dab85/attachment.html
[Pw_forum] Bulk Modulus Calculation
it seems that you don't know how bulk modulus is actually calculated. It is -V(d^2E/dV^2). So you need to vary the volume, calculate total energy then fit the data to equation of states (I think ev.f90 do this job, I am not so sure. But in any case, you can always fit these data to equation of states by any other programs or codes). Once you have equation of states, calculate -V(d^2E/dV^2) at the minimum >>> this is bulk modulus. I suggest that you should have look a http://www.pwscf.org/wiki/index.php/QESB09 and follow the Lab tutorial on Monday 20, July 2009. The week1_day1_exersice1 is about optimizing lattice parameter, equation of states (that includes bulk modulus) -- Duy Le PhD Student Department of Physics University of Central Florida. "Men don't need hand to do things" On Tue, Jan 4, 2011 at 5:06 PM, Tram Bui wrote: > Hi All, > Hope everyone had great holidays, I had a question before regarding the > Bulk Modulus calculation (ev.f90) But I'm having hard time understand? the > file and don't know how to use the ev.f to help me calculate the bulk > modulus if I have an input file is like below and the structure is zinc > blend (b-SiC). Would you help me if you get a chance? here is my file and > you can run it in xcyrsden to see the structure. > > &CONTROL > ?? calculation='scf' > ?? restart_mode='from_scratch', > ?? prefix='Silicon', > ?? tprnfor=.true. > ?? pseudo_dir='/home/trambui/QE/espresso-4.2.1/pseudo', > ?? outdir='./tmp7/', > / > &SYSTEM > ?? ibrav=2, celldm(1)=8.33, nat=2, ntyp=2, > ?? ecutwfc= 30, > / > &ELECTRONS > ?? diagonalization= 'david', > ?? mixing_mode= 'plain', > ?? mixing_beta= 0.5, > ?? conv_thr= 1.0d-7, > / > ATOMIC_SPECIES > Si 28.086 Si.pbe-n-van.UPF > ?C 12.011 C.pbe-van_ak.UPF > ATOMIC_POSITIONS > Si 0.00 0.00 0.00 > ?C 0.25 0.25 0.25 > K_POINTS automatic > 10 10 10 0 0 0 > > I really appreciate your helps! > > Tram Bui > > B.S. Materials Science & Engineering > trambui at u.boisestate.edu > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > >
[Pw_forum] Bulk Modulus Calculation
Hi Tram,
To use ev.x, you need a file with the lattice constants and total energies
tabulated.
Here is a shell script that will take an input file, adjust the lattice
parameter over a small range (+/- 2% in my example) and collect the lattice
parameters and total energies in an file I call ev.dat (note you must have sed
and awk available):
#!/bin/sh
EXE=pw.x
IN=
OUT=`echo $IN | sed 's/\.in/\.out/'`
DAT=ev.dat
A0=
for fac in -0.020 -0.015 -0.010 -0.005 0.000 0.005 0.010 0.015 0.020
do
alatt=`echo "$fac $A0" | awk '{printf "%5.3f",(1+$1)*$2}'`
mkdir $alatt
sed "/celldm(1)/s/=.*/= $alatt/" $IN > $alatt/$IN
cd $alatt
$EXE < $IN >& $OUT
e=`grep '!total energy' $OUT | tail -1 | awk '{printf
"%16.10f\n",$5}'`
echo "$alatt$e" >> ../$DAT
cd ..
done
Be sure that the pw.x executable is in your shell path and define your own
input file name and lattice constant. You may also adjust the range you want
to sample for the bulk modulus.
Once, you've run the script to get your energies, run ev.x, choose au as the
units, choose the appropriate cell shape (fcc in your case), put ev.dat as the
input file and name the output whatever you want. Pick the equation of state
you want to use, and the results will appear in the output file you named.
I hope this helps. Anyone with additional and/or corrective advice, please
chime in.
--William
*
William D. Parker phone: (630) 252-1775
Computational Postdoctoral Fellow fax: (630) 252-4798
MSD-212, Rm. C-215
Argonne National Laboratory
9700 S. Cass Ave.
Argonne, IL 60439
*
On Jan 4, 2011, at 4:06 PM, Tram Bui wrote:
> Hi All,
> Hope everyone had great holidays, I had a question before regarding the
> Bulk Modulus calculation (ev.f90) But I'm having hard time understand the
> file and don't know how to use the ev.f to help me calculate the bulk modulus
> if I have an input file is like below and the structure is zinc blend
> (b-SiC). Would you help me if you get a chance? here is my file and you can
> run it in xcyrsden to see the structure.
>
> &CONTROL
>calculation='scf'
>restart_mode='from_scratch',
>prefix='Silicon',
>tprnfor=.true.
>pseudo_dir='/home/trambui/QE/espresso-4.2.1/pseudo',
>outdir='./tmp7/',
> /
> &SYSTEM
>ibrav=2, celldm(1)=8.33, nat=2, ntyp=2,
>ecutwfc= 30,
> /
> &ELECTRONS
>diagonalization= 'david',
>mixing_mode= 'plain',
>mixing_beta= 0.5,
>conv_thr= 1.0d-7,
> /
> ATOMIC_SPECIES
> Si 28.086 Si.pbe-n-van.UPF
> C 12.011 C.pbe-van_ak.UPF
> ATOMIC_POSITIONS
> Si 0.00 0.00 0.00
> C 0.25 0.25 0.25
> K_POINTS automatic
> 10 10 10 0 0 0
>
> I really appreciate your helps!
>
> Tram Bui
>
> B.S. Materials Science & Engineering
> trambui at u.boisestate.edu
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
[Pw_forum] Bulk Modulus Calculation
Hi, Use attached ev.f90 instead. I think output file is quite self-explanatory. All you need is just answering correctly questions requested by the program (ev.x). Besides, you need to learn about the methods to calculate ground state parameters, including bulk modulus. See, at least, VLab lecture given by R. Wentzcovitch , http://www.vlab.msi.umn.edu/events/download/vlab_lectures/renata/lecture3.pdf I also recommend to search this site to find very good lectures by another authors. I remember, last year there was a PRB paper concerning applications of different methods (Phys. Rev. B 78, 214108 (2008) ). Bests, Eyvaz --- Prof. Eyvaz Isaev, Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com From: Tram Bui To: PWSCF Forum Sent: Tue, January 4, 2011 11:06:44 PM Subject: [Pw_forum] Bulk Modulus Calculation Hi All, Hope everyone had great holidays, I had a question before regarding the Bulk Modulus calculation (ev.f90) But I'm having hard time understand the file and don't know how to use the ev.f to help me calculate the bulk modulus if I have an input file is like below and the structure is zinc blend (b-SiC). Would you help me if you get a chance? here is my file and you can run it in xcyrsden to see the structure. &CONTROL calculation='scf' restart_mode='from_scratch', prefix='Silicon', tprnfor=.true. pseudo_dir='/home/trambui/QE/espresso-4.2.1/pseudo', outdir='./tmp7/', / &SYSTEM ibrav=2, celldm(1)=8.33, nat=2, ntyp=2, ecutwfc= 30, / &ELECTRONS diagonalization= 'david', mixing_mode= 'plain', mixing_beta= 0.5, conv_thr= 1.0d-7, / ATOMIC_SPECIES Si 28.086 Si.pbe-n-van.UPF C 12.011 C.pbe-van_ak.UPF ATOMIC_POSITIONS Si 0.00 0.00 0.00 C 0.25 0.25 0.25 K_POINTS automatic 10 10 10 0 0 0 I really appreciate your helps! Tram Bui B.S. Materials Science & Engineering trambui at u.boisestate.edu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110104/1ebcda94/attachment-0001.htm -- next part -- A non-text attachment was scrubbed... Name: ev.f90 Type: application/octet-stream Size: 12419 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20110104/1ebcda94/attachment-0002.obj -- next part -- A non-text attachment was scrubbed... Name: out_test Type: application/octet-stream Size: 1394 bytes Desc: not available Url : http://www.democritos.it/pipermail/pw_forum/attachments/20110104/1ebcda94/attachment-0003.obj
[Pw_forum] Bulk Modulus Calculation
Hi All, Hope everyone had great holidays, I had a question before regarding the Bulk Modulus calculation (ev.f90) But I'm having hard time understand the file and don't know how to use the ev.f to help me calculate the bulk modulus if I have an input file is like below and the structure is zinc blend (b-SiC). Would you help me if you get a chance? here is my file and you can run it in xcyrsden to see the structure. &CONTROL calculation='scf' restart_mode='from_scratch', prefix='Silicon', tprnfor=.true. pseudo_dir='/home/trambui/QE/espresso-4.2.1/pseudo', outdir='./tmp7/', / &SYSTEM ibrav=2, celldm(1)=8.33, nat=2, ntyp=2, ecutwfc= 30, / &ELECTRONS diagonalization= 'david', mixing_mode= 'plain', mixing_beta= 0.5, conv_thr= 1.0d-7, / ATOMIC_SPECIES Si 28.086 Si.pbe-n-van.UPF C 12.011 C.pbe-van_ak.UPF ATOMIC_POSITIONS Si 0.00 0.00 0.00 C 0.25 0.25 0.25 K_POINTS automatic 10 10 10 0 0 0 I really appreciate your helps! Tram Bui B.S. Materials Science & Engineering trambui at u.boisestate.edu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110104/f3118ab0/attachment.htm
[Pw_forum] Bulk Modulus calculation
ev.f90 and ev.x should be in [WHEREEVER IT IS]espressso-X/pwtools/ ev.x can be also found in [WHEREEVER IT IS]espressso-X/bin If you can not find executable file of ev.x, you should make it with: $ cd [WHEREEVER IT IS]espressso-X/ $ make tools -- Duy Le PhD Student Department of Physics University of Central Florida. "Men don't need hand to do things" On Wed, Dec 29, 2010 at 6:16 PM, Tram Bui wrote: > Dear All, > ??? Hope everyone is having a great Holiday. would you please help me out > with this, I'm looking for the "ev.f" that help to calculate the bulk > modulus of a material. But I couldn't find it any where, please let me know > where and how I can find that and use it to calculate for the bulk modulus, > B. > > Thank you so much, > > Tram Bui > > B.S. Materials Science & Engineering > trambui at u.boisestate.edu > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > >
[Pw_forum] Bulk Modulus calculation
Dear All, Hope everyone is having a great Holiday. would you please help me out with this, I'm looking for the "ev.f" that help to calculate the bulk modulus of a material. But I couldn't find it any where, please let me know where and how I can find that and use it to calculate for the bulk modulus, B. Thank you so much, Tram Bui B.S. Materials Science & Engineering trambui at u.boisestate.edu -- next part -- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101229/542f0d3f/attachment.htm
