[Pw_forum] Integrated DOS in dos.x output is not consistent in nelec
Dear PWscf Users.
I had calculated PbTiO3 dos by the following procedure,
1) I did scf calculation
2) then I increase KPOINTS and do non-scf run,
3) finally I had calculate total DOS by dos.x
The all valence electron number nelec = 44
and the Fermi Enegy output which lay in the energy gap
is ( in 2) process I set occupation='tetrahedra' )
the Fermi Enegy is 11.1368 eV
But I see the output total DOS in 3) around Fermi Energy
eVdos(E) Int dos(E)
10.850 0.E+00 0.3353E+02
10.900 0.E+00 0.3353E+02
10.950 0.E+00 0.3353E+02
11.000 0.E+00 0.3353E+02
11.050 0.E+00 0.3353E+02
11.100 0.E+00 0.3353E+02
11.150 0.E+00 0.3353E+02
11.200 0.E+00 0.3353E+02
11.250 0.E+00 0.3353E+02
11.300 0.E+00 0.3353E+02
11.350 0.E+00 0.3353E+02
11.400 0.E+00 0.3353E+02
11.450 0.E+00 0.3353E+02
11.500 0.E+00 0.3353E+02
The Integrated Dos around Fermi Enegy for the case of insulater
it must be nelec/2 = 22 ( for non-spin polarized case)
but, it seems different number 33.5333
Why such a problem have happen?
Sincerely,
Yukihiro Okuno.
With my input file are
&control
calculation = 'scf',
restart_mode = 'from_scratch',
pseudo_dir = '/home/okuno/PWSCF/espresso-3.1.1/pseudo/',
outdir = './',
prefix = "PbTiO3"
/
&system
ibrav=6
celldm(1)=7.36203352272
celldm(3)=1.07
nat=5
ntyp=3
nbnd=26
ecutwfc=30.0
occupations = 'fixed'
degauss=0.00
/
&electrons
conv_thr = 1e-12,
mixing_beta=0.3,
/
ATOMIC_SPECIES
Pb207.2 Pb.vdb.UPF
Ti47.867Ti.vdb.UPF
O 15.9994 O.vdb.UPF
ATOMIC_POSITIONS {crystal}
Pb 0.0 0.0 -0.01472
Ti 0.5 0.5 0.533084193
O0.0 0.5 0.615412576
O0.5 0.0 0.615412576
O0.5 0.5 0.111205097
K_POINTS {automatic}
4 4 4 1 1 1
and process 2) for nscf run for DOS
&control
calculation = 'nscf',
pseudo_dir = '/home/okuno/PWSCF/espresso-3.1.1/pseudo/',
outdir = './',
prefix = 'PbTiO3'
/
&system
ibrav=6
celldm(1)=7.36203352272
celldm(3)=1.07
nat=5
ntyp=3
nbnd=26
ecutwfc=30.0
occupations = 'tetrahedra'
/
&electrons
conv_thr = 1e-12,
mixing_beta=0.3,
/
ATOMIC_SPECIES
Pb207.2 Pb.vdb.UPF
Ti47.867Ti.vdb.UPF
O 15.9994 O.vdb.UPF
ATOMIC_POSITIONS {crystal}
Pb 0.0 0.0 -0.01472
Ti 0.5 0.5 0.533084193
O0.0 0.5 0.615412576
O0.5 0.0 0.615412576
O0.5 0.5 0.111205097
K_POINTS {automatic}
8 8 8 1 1 1
and process 3) for dos.x input file is
&inputpp
outdir='/home/okuno/PWSCF/espresso-3.1.1/Work/PbTiO3',
prefix='PbTiO3',
fildos='PbTiO3.dos',
Emin=-15.0, Emax=20.0, DeltaE=0.05
/
[Pw_forum] Electron affinity calculation
Why the average hartree potential? Shouldn't it be the total potential averaged in the median plane in-between the slabs? Best Regards, Alexander Shaposhnikov On Wednesday 31 January 2007 21:14, Davide Ceresoli wrote: > Alexander Shaposhnikov wrote: > > I have tried several slab models and the first conduction band > > is still meaningless, i.e. much higher than it should be in real > > crystall. I have not tried to optimize the structures though. > > Have you subtracted the value of the vacuum level from the edge > of the conduction band? in a slab geometry the vacuum level is > given by the average hartree potential in the vacuum region, > in between the slab. > > HTH > > Davide > > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum
[Pw_forum] a question about a calculation on a relatively large system
0116 > C 0.7607 0.91281 0.5116 > C 0.7393 0.08719 0.0116 > C 0.2393 0.41281 0.4884 > C 0.2607 0.58719 0.9884 > C 0.3266 0.04374 0.4613 > C 0.1734 0.95626 0.9613 > C 0.6734 0.54374 0.5387 > C 0.8266 0.45626 0.0387 > C 0.6734 0.95626 0.5387 > C 0.8266 0.04374 0.0387 > C 0.3266 0.45626 0.4613 > C 0.1734 0.54374 0.9613 > C 0.3386 0.0266 0.3431 > C 0.1614 0.9734 0.8431 > C 0.6614 0.5266 0.6569 > C 0.8386 0.4734 0.1569 > C 0.6614 0.9734 0.6569 > C 0.8386 0.0266 0.1569 > C 0.3386 0.4734 0.3431 > C 0.1614 0.5266 0.8431 > C 0.2643 0.05242 0.2492 > C 0.2357 0.94758 0.7492 > C 0.7357 0.55242 0.7508 > C 0.7643 0.44758 0.2508 > C 0.7357 0.94758 0.7508 > C 0.7643 0.05242 0.2508 > C 0.2643 0.44758 0.2492 > C 0.2357 0.55242 0.7492 > C 0.177 0.09588 0.2738 > C 0.323 0.90412 0.7738 > C 0.823 0.59588 0.7262 > C 0.677 0.40412 0.2262 > C 0.823 0.90412 0.7262 > C 0.677 0.09588 0.2262 > C 0.177 0.40412 0.2738 > C 0.323 0.59588 0.7738 > C 0.2052 0.1385 0.9741 > C 0.2948 0.8615 0.4741 > C 0.7948 0.6385 0.0259 > C 0.7052 0.3615 0.5259 > C 0.7948 0.8615 0.0259 > C 0.7052 0.1385 0.5259 > C 0.2052 0.3615 0.9741 > C 0.2948 0.6385 0.4741 > C 0.2871 0.09507 0.9432 > C 0.2129 0.90493 0.4432 > C 0.7129 0.59507 0.0568 > C 0.7871 0.40493 0.5568 > C 0.7129 0.90493 0.0568 > C 0.7871 0.09507 0.5568 > C 0.2871 0.40493 0.9432 > C 0.2129 0.59507 0.4432 > C 0.3808 0.09512 0.8396 > C 0.1192 0.90488 0.3396 > C 0.6192 0.59512 0.1604 > C 0.8808 0.40488 0.6604 > C 0.6192 0.90488 0.1604 > C 0.8808 0.09512 0.6604 > C 0.3808 0.40488 0.8396 > C 0.1192 0.59512 0.3396 > C 0.3916 0.13816 0.7686 > C 0.1084 0.86184 0.2686 > C 0.6084 0.63816 0.2314 > C 0.8916 0.36184 0.7314 > C 0.6084 0.86184 0.2314 > C 0.8916 0.13816 0.7314 > C 0.3916 0.36184 0.7686 > C 0.1084 0.63816 0.2686 > C 0.3093 0.18228 0.7974 > C 0.1907 0.81772 0.2974 > C 0.6907 0.68228 0.2026 > C 0.8093 0.31772 0.7026 > C 0.6907 0.81772 0.2026 > C 0.8093 0.18228 0.7026 > C 0.3093 0.31772 0.7974 > C 0.1907 0.68228 0.2974 > C 0.2145 0.18316 0.89954 > C 0.2855 0.81684 0.39954 > C 0.7855 0.68316 0.10046 > C 0.7145 0.31684 0.60046 > C 0.7855 0.81684 0.10046 > C 0.7145 0.18316 0.60046 > C 0.2145 0.31684 0.89954 > C 0.2855 0.68316 0.39954 > H 0.1087 0.1988 0.5547 > H 0.3913 0.8012 0.0547 > H 0.8913 0.6988 0.4453 > H 0.6087 0.3012 0.9453 > H 0.8913 0.8012 0.4453 > H 0.6087 0.1988 0.9453 > H 0.1087 0.3012 0.5547 > H 0.3913 0.6988 0.0547 > H 0.2312 0.0989 0.5694 > H 0.2688 0.9011 0.0694 > H 0.7688 0.5989 0.4306 > H 0.7312 0.4011 0.9306 > H 0.7688 0.9011 0.4306 > H 0.7312 0.0989 0.9306 > H 0.2312 0.4011 0.5694 > H 0.2688 0.5989 0.0694 > H 0.3783 0.0258 0.5242 > H 0.1217 0.9742 0.0242 > H 0.6217 0.5258 0.4758 > H 0.8783 0.4742 0.9758 > H 0.6217 0.9742 0.4758 > H 0.8783 0.0258 0.9758 > H 0.3783 0.4742 0.5242 > H 0.1217 0.5258 0.0242 > H 0.3981 0.9969 0.3259 > H 0.1019 0.0031 0.8259 > H 0.6019 0.4969 0.6741 > H 0.8981 0.5031 0.1741 > H 0.6019 0.0031 0.6741 > H 0.8981 0.9969 0.1741 > H 0.3981 0.5031 0.3259 > H 0.1019 0.4969 0.8259 > H 0.2733 0.0403 0.1686 > H 0.2267 0.9597 0.6686 > H 0.7267 0.5403 0.8314 > H 0.7733 0.4597 0.3314 > H 0.7267 0.9597 0.8314 > H 0.7733 0.0403 0.3314 > H 0.2733 0.4597 0.1686 > H 0.2267 0.5403 0.6686 > H 0.28 0.0654 0.9919 > H 0.22 0.9346 0.4919 > H 0.72 0.5654 0.0081 > H 0.78 0.4346 0.5081 > H 0.72 0.9346 0.0081 > H 0.78 0.0654 0.5081 > H 0.28 0.4346 0.9919 > H 0.22 0.5654 0.4919 > H 0.4373 0.0653 0.8181 > H 0.0627 0.9347 0.3181 > H 0.5627 0.5653 0.1819 > H 0.9373 0.4347 0.6819 > H 0.5627 0.9347 0.1819 > H 0.9373 0.0653 0.6819 > H 0.4373 0.4347 0.8181 > H 0.0627 0.5653 0.3181 > H 0.4562 0.1377 0.6988 > H 0.0438 0.8623 0.1988 > H 0.5438 0.6377 0.3012 > H 0.9562 0.3623 0.8012 > H 0.5438 0.8623 0.3012 > H 0.9562 0.1377 0.8012 > H 0.4562 0.3623 0.6988 > H 0.0438 0.6377 0.1988 > H 0.3178 0.2116 0.7476 > H 0.1822 0.7884 0.2476 > H 0.6822 0.7116 0.2524 > H 0.8178 0.2884 0.7524 > H 0.6822 0.7884 0.2524 > H 0.8178 0.2116 0.7524 > H 0.3178 0.2884 0.7476 > H 0.1822 0.7116 0.2476 > > -- Nichols A. Romero, Ph.D. 1613 Denise Dr. Apt. D Forest Hill, MD 21050 443-567-8328 (C) 410-306-0709 (O) -- next part -- An HTML attachment was scrubbed... URL: /pipermail/attachments/20070131/88a7b752/attachment.htm
[Pw_forum] Electron affinity calculation
I have tried several slab models and the first conduction band is still meaningless, i.e. much higher than it should be in real crystall. I have not tried to optimize the structures though. I guess, i have to 1. Optimize the structure. 2. Remove some electrons from the system, hoping to create surface charge. Am i right here? Best Regards, Alexander Shaposhnikov On Saturday 27 January 2007 14:22, Alexander Shaposhnikov wrote: > Hello Dr. Baroni, > > Thank you, i was thinking about surface myself, > good to know i was in the right direction! > I will try to create slab surface model. > > Best Regards, > Alexander Shaposhnkov > > On Saturday 27 January 2007 13:54, Stefano Baroni wrote: > > On Jan 27, 2007, at 8:39 AM, Alexander Shaposhnikov wrote: > > > My question is, what is the established approach for the > > > calculations of > > > electron affinity for the plane wave band dft calculations? > > > > I believe, you should first ask (and answer) the preliminary > > question: what makes " ... the first conduction band ... > > meaningful ..?.. " The answer does not depend on the theoretical > > approach (DFT), nor on the basis set (plane waves), but on nature: > > the surface. So, in order to calculate electron affinities in an > > extended system you have to simulate "the place the added electron > > comes from", i.e. the vacuum, and the interface between that place > > and the solid, i.e. a surface. > > > > Hope this clarifies a bit. > > > > Stefano > > > > --- > > Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - > > Trieste > > [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) > > > > Please, if possible, don't send me MS Word or PowerPoint attachments > > Why? See: http://www.gnu.org/philosophy/no-word-attachments.html > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum
[Pw_forum] lambda calculation from the a2F(w) files
Dear pw_users, does someone know which is the normalization of the a2F function generated by the espresso 3.2 during an electron-phonon calculation? We tried to reproduce the lambda values generated by matdyn.f90 using the a2F(w) files. At first, we used the formula that appears in the majority of the papers, including the McMillan and the Allen-Dynes papers that is (lambda=2*\int a2F/w dw), and we could not obtain the same results. A quick inspection of the source code suggests that in order to used the above formula, the a2F values should first be divided by 2*pi. Or what is the same, one should instead use the formula (lambda=(1/\pi)*\int a2F/w dw) that seems to be implemented in matdyn. Is this correct? Thanks in advance, Alexander
[Pw_forum] Electron affinity calculation
because they tend to the same value far out in the vacuum, but the Hartree potential does so more fast than the total potential. can you tell why? SB On Jan 31, 2007, at 5:09 PM, Alexander Shaposhnikov wrote: > Why the average hartree potential? > Shouldn't it be the total potential averaged in the median plane > in-between the slabs? > > Best Regards, > Alexander Shaposhnikov > > > On Wednesday 31 January 2007 21:14, Davide Ceresoli wrote: >> Alexander Shaposhnikov wrote: >>> I have tried several slab models and the first conduction band >>> is still meaningless, i.e. much higher than it should be in real >>> crystall. I have not tried to optimize the structures though. >> >> Have you subtracted the value of the vacuum level from the edge >> of the conduction band? in a slab geometry the vacuum level is >> given by the average hartree potential in the vacuum region, >> in between the slab. >> >> HTH >> >> Davide >> >> >> ___ >> 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 --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -- next part -- An HTML attachment was scrubbed... URL: /pipermail/attachments/20070131/ff7d86dd/attachment.htm
[Pw_forum] Electron affinity calculation
Alexander Shaposhnikov wrote: > Why the average hartree potential? > Shouldn't it be the total potential averaged in the median plane > in-between the slabs? > All right. It's the electrostatic potential. I generally use plot_num = 11 (11=the V_bare + V_H potential) in postprocessing.
[Pw_forum] a question about a calculation on a relatively large system
0.6192 0.90488 0.1604 C 0.8808 0.09512 0.6604 C 0.3808 0.40488 0.8396 C 0.1192 0.59512 0.3396 C 0.3916 0.13816 0.7686 C 0.1084 0.86184 0.2686 C 0.6084 0.63816 0.2314 C 0.8916 0.36184 0.7314 C 0.6084 0.86184 0.2314 C 0.8916 0.13816 0.7314 C 0.3916 0.36184 0.7686 C 0.1084 0.63816 0.2686 C 0.3093 0.18228 0.7974 C 0.1907 0.81772 0.2974 C 0.6907 0.68228 0.2026 C 0.8093 0.31772 0.7026 C 0.6907 0.81772 0.2026 C 0.8093 0.18228 0.7026 C 0.3093 0.31772 0.7974 C 0.1907 0.68228 0.2974 C 0.2145 0.18316 0.89954 C 0.2855 0.81684 0.39954 C 0.7855 0.68316 0.10046 C 0.7145 0.31684 0.60046 C 0.7855 0.81684 0.10046 C 0.7145 0.18316 0.60046 C 0.2145 0.31684 0.89954 C 0.2855 0.68316 0.39954 H 0.1087 0.1988 0.5547 H 0.3913 0.8012 0.0547 H 0.8913 0.6988 0.4453 H 0.6087 0.3012 0.9453 H 0.8913 0.8012 0.4453 H 0.6087 0.1988 0.9453 H 0.1087 0.3012 0.5547 H 0.3913 0.6988 0.0547 H 0.2312 0.0989 0.5694 H 0.2688 0.9011 0.0694 H 0.7688 0.5989 0.4306 H 0.7312 0.4011 0.9306 H 0.7688 0.9011 0.4306 H 0.7312 0.0989 0.9306 H 0.2312 0.4011 0.5694 H 0.2688 0.5989 0.0694 H 0.3783 0.0258 0.5242 H 0.1217 0.9742 0.0242 H 0.6217 0.5258 0.4758 H 0.8783 0.4742 0.9758 H 0.6217 0.9742 0.4758 H 0.8783 0.0258 0.9758 H 0.3783 0.4742 0.5242 H 0.1217 0.5258 0.0242 H 0.3981 0.9969 0.3259 H 0.1019 0.0031 0.8259 H 0.6019 0.4969 0.6741 H 0.8981 0.5031 0.1741 H 0.6019 0.0031 0.6741 H 0.8981 0.9969 0.1741 H 0.3981 0.5031 0.3259 H 0.1019 0.4969 0.8259 H 0.2733 0.0403 0.1686 H 0.2267 0.9597 0.6686 H 0.7267 0.5403 0.8314 H 0.7733 0.4597 0.3314 H 0.7267 0.9597 0.8314 H 0.7733 0.0403 0.3314 H 0.2733 0.4597 0.1686 H 0.2267 0.5403 0.6686 H 0.28 0.0654 0.9919 H 0.22 0.9346 0.4919 H 0.72 0.5654 0.0081 H 0.78 0.4346 0.5081 H 0.72 0.9346 0.0081 H 0.78 0.0654 0.5081 H 0.28 0.4346 0.9919 H 0.22 0.5654 0.4919 H 0.4373 0.0653 0.8181 H 0.0627 0.9347 0.3181 H 0.5627 0.5653 0.1819 H 0.9373 0.4347 0.6819 H 0.5627 0.9347 0.1819 H 0.9373 0.0653 0.6819 H 0.4373 0.4347 0.8181 H 0.0627 0.5653 0.3181 H 0.4562 0.1377 0.6988 H 0.0438 0.8623 0.1988 H 0.5438 0.6377 0.3012 H 0.9562 0.3623 0.8012 H 0.5438 0.8623 0.3012 H 0.9562 0.1377 0.8012 H 0.4562 0.3623 0.6988 H 0.0438 0.6377 0.1988 H 0.3178 0.2116 0.7476 H 0.1822 0.7884 0.2476 H 0.6822 0.7116 0.2524 H 0.8178 0.2884 0.7524 H 0.6822 0.7884 0.2524 H 0.8178 0.2116 0.7524 H 0.3178 0.2884 0.7476 H 0.1822 0.7116 0.2476 ------ next part -- An HTML attachment was scrubbed... URL: /pipermail/attachments/20070131/5bf7e270/attachment.htm
[Pw_forum] Electron affinity calculation
On Jan 31, 2007, at 3:50 PM, Alexander Shaposhnikov wrote: > > I have tried several slab models and the first conduction band > is still meaningless, i.e. much higher than it should be in real > crystall. the absolute value of the energy levels are of course as meaningless as they are for a bulk calculation, and for the same reason: the average electrostatic potential of an infinite solid is ill defined (periodically repeated slabs do constitute an infinite, periodic, system). What you ought to look after is the position of individual energy levels *with respect to the value of the potential in the vacuum region*. > I have not tried to optimize the structures though. > > I guess, i have to > 1. Optimize the structure. fine > 2. Remove some electrons from the system, hoping to create surface > charge. I think that the value of the lumo energy with respect to the vacuum potential should be a fair estimate of the electron affinity you are looking for. S. --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -- next part -- An HTML attachment was scrubbed... URL: /pipermail/attachments/20070131/898aba84/attachment.htm
[Pw_forum] Electron affinity calculation
Alexander Shaposhnikov wrote: > I have tried several slab models and the first conduction band > is still meaningless, i.e. much higher than it should be in real crystall. > I have not tried to optimize the structures though. Have you subtracted the value of the vacuum level from the edge of the conduction band? in a slab geometry the vacuum level is given by the average hartree potential in the vacuum region, in between the slab. HTH Davide
[Pw_forum] Integrated DOS in dos.x output is not consistent in nelec
Dear Yukihiro, > > The all valence electron number nelec = 44 > [] > but, it seems different number 33.5333 > > Why such a problem have happen? > > > &inputpp > outdir='/home/okuno/PWSCF/espresso-3.1.1/Work/PbTiO3', > prefix='PbTiO3', > fildos='PbTiO3.dos', > Emin=-15.0, Emax=20.0, DeltaE=0.05 > / > I suspect your problems are due to the values you specified for Emin=-15.0 or DeltaE=0.05 small numbers of electron from the DOS may be due to the fact Emin is not below the lowest eigenvalue (my suggestion is to avoid providing Emin except you really need it)... a second problem may be connected with the DeltaE value: since the integration of the DOS is performed on the output energy grid, a too coarse grid may result in wrong integration... ( note that the default value for DeltaE is 0.01 eV ) hope it helps andrea -- Andrea Ferretti National Research Center S3, CNR-INFM ( http://s3.infm.it ) Dipartimento di Fisica, Universita' di Modena e Reggio Emilia Via Campi 213/A I-41100 Modena, Italy Tel: +39 059 2055301 Fax: +39 059 374794 Skype: andrea_ferretti URL: http://www.nanoscience.unimo.it Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
[Pw_forum] About (7,3) nanowire coordinates
Dear All, I would like to generate all of the 85 coordinates of the (7,3) Au chiral nanowire using PWScf, which has already been done a long ago by Dr. Andrea (Ref. Science, v291,pp290,2001). I would greatly appreciate if you could please provide me the input file for this. What would be the input file for the (6,0) nanowire as well? With best regards, Arijit -- next part -- An HTML attachment was scrubbed... URL: /pipermail/attachments/20070131/539a6e5d/attachment.htm
[Pw_forum] On tne optimization error in PbTiO3
Dear PWscf Users.
I'm now working the optimization of PbTiO3
But in the process of calculation, my calculation
stopped with an error like below
CASE: energy_new > energy_old
new trust radius= 0.499856 bohr
trust_radius < trust_radius_min
resetting bfgs history
%%
from bfgs : error # 1
bfgs history already reset at previous step
%%
stopping ...
What is wrong and how to treat such an erro?
This is my input file
&control
calculation = 'relax',
restart_mode = 'from_scratch',
pseudo_dir = '/home/okuno/PWSCF/espresso-3.1.1/pseudo/',
outdir = './',
forc_conv_thr = 1.0D-5
/
&system
ibrav=6
celldm(1)=7.36203352272
celldm(3)=1.07
nat=5
ntyp=3
nbnd=25
ecutwfc=30.0
occupations = 'fixed'
degauss=0.00
/
&electrons
conv_thr = 1e-7,
mixing_beta=0.3,
/
&IONS
ion_dynamics='bfgs'
bfgs_ndim=3
pot_extrapolation = "second_order"
wfc_extrapolation = "second_order"
/
ATOMIC_SPECIES
Pb207.2 Pb.vdb.UPF
Ti47.867Ti.vdb.UPF
O 15.9994 O.vdb.UPF
ATOMIC_POSITIONS {crystal}
Pb 0.0 0.0 0.0
Ti 0.5 0.5 0.53402
O0.0 0.5 0.61123
O0.5 0.0 0.61123
O0.5 0.5 0.10391
K_POINTS {automatic}
4 4 4 1 1 1
[Pw_forum] On tne optimization error in PbTiO3
In general calculated energies are a little noisy (due to insufficient
scf accuracy and/or
insufficient accuracy in the integration of the XC functional on the FFT
real space grid).
Moreover Energies and forces are slightly inconsistent (due to
insufficient scf accuracy).
Hence it is pointless to pretend a convergence in the relaxation below
this noise level.
When the history of the relaxation makes no sense the code reduce the
size of the tipical
step and restart the history, but if the step is so small that you are
already digging below
the noise level this does not help.
By the way forc_conv_thr = 1.0D-5 is an extremey strict threshold.
default value is 1.0d-3 and usually is alread fine. 1.0d-4 should be
more than
enough for any purpouse.
stefano
yukihiro_okuno at fujifilm.co.jp wrote:
>Dear PWscf Users.
>
>I'm now working the optimization of PbTiO3
>
>But in the process of calculation, my calculation
>
>stopped with an error like below
>
> CASE: energy_new > energy_old
>
> new trust radius= 0.499856 bohr
>
> trust_radius < trust_radius_min
>
> resetting bfgs history
>
>
>
>%%
> from bfgs : error # 1
> bfgs history already reset at previous step
>
>%%
>
> stopping ...
>
>
>What is wrong and how to treat such an erro?
>
>This is my input file
>
>&control
>calculation = 'relax',
>restart_mode = 'from_scratch',
>pseudo_dir = '/home/okuno/PWSCF/espresso-3.1.1/pseudo/',
>outdir = './',
>forc_conv_thr = 1.0D-5
> /
> &system
>ibrav=6
>celldm(1)=7.36203352272
>celldm(3)=1.07
>nat=5
>ntyp=3
>nbnd=25
>ecutwfc=30.0
>occupations = 'fixed'
>degauss=0.00
> /
> &electrons
>conv_thr = 1e-7,
>mixing_beta=0.3,
> /
>&IONS
> ion_dynamics='bfgs'
> bfgs_ndim=3
> pot_extrapolation = "second_order"
> wfc_extrapolation = "second_order"
>/
>ATOMIC_SPECIES
> Pb207.2 Pb.vdb.UPF
> Ti47.867Ti.vdb.UPF
> O 15.9994 O.vdb.UPF
>ATOMIC_POSITIONS {crystal}
>Pb 0.0 0.0 0.0
>Ti 0.5 0.5 0.53402
>O0.0 0.5 0.61123
>O0.5 0.0 0.61123
>O0.5 0.5 0.10391
>K_POINTS {automatic}
> 4 4 4 1 1 1
>
>
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>Pw_forum at pwscf.org
>http://www.democritos.it/mailman/listinfo/pw_forum
>
>
[Pw_forum] Plot phonon dispersion
Hi, Eyvas, And as and on conditions it is possible to receive these programs? Igor Eyvaz Isaev ?: > Hi, > > How it is possible (for example - plotband) from .freq to > construct the postscript plot file for a phonon dispersion ? > > It is possible, as example, using my little program and script. > > Bests, > Eyvaz. > > > Igor Shein > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > > Never Miss an Email > Stay connected with Yahoo! Mail on your mobile. Get started! > http://mobile.yahoo.com/services?promote=mail > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- PhD Igor R. Shein Leading researcher Insitute of the Solid State Chemistry Ural Branch Of the Russial Academy of Sciences Pervomaiskaya st. 91, 620041 Yekaterinburg, Russia Tel: +7 343 362 3387 Fax: +7 343 374 4495
[Pw_forum] Induced charge density, phonon.
Dear users. I was wondering if I could get some help regarding the induced charge density at a surface due to a phonon at a specific q-point. The surface is based on the slab model. For a specific mode (surface mode) at a specific q-parallel-point (SBZ zone boundary) I would like to extract the induced charge density in real space along the slab z-axis, delta-n(R,z) where R=(x,y) (a point i the slab plane). I have tried with some lighter examples to use and try to understand the option in INPUT_PH namely fildrho. All this gave was a lot of zeros, regardless at which q-point this was done. Any explanations why? I've would be pleased for any ideas of how to access this problem and how to get the desired charge density in real space. Thank you in advance. Best regards Vasse -- ___ Vasile Chis, Ph.D Student Interface Modelling Group Department of Physics G?teborgs Universitet Fysikg?rden 6B S-412 96 G?teborg, SWEDEN tel:+46 (0) 31 7723338 mobile :+46 (0) 70 8348867 fax. :+46 (0) 31 7723367 email :Vasile.Chis at physics.gu.se ___
[Pw_forum] On tne optimization error in PbTiO3
On Wed, 31 Jan 2007, degironc wrote:
hi,
let me translate this into 'beginner speak':
the problem here essentially boils down to: you cannot get more
accuracy on one property, if you do not calculate the property it
depends on accurate enough. if one changes a parameter, one has to
check, what other parameters need to be changed as well.
in case of geometry optimization. if you want to converge the
geometry very accurately (as stefano pointed out, 1.0e-5 is
extreme), you first have to make sure that you compute the forces
on the atoms accurate enough. that accuracy depends primarily on
the basis set size (plane wave energy cutoff) and the convergence
parameter for single point energy. so you have to do a run of
single point calculations where you print out the forces to find
out how high you have to crank up the PW-cutoff and how tight
you have to converge the wavefunction to get forces that accurate.
the second point is the 'noise' from evaluating the xc-functionals
(especially when you include gradient correction). and interpolated
with splines, with a very coarse grid the forces may be pretty random.
now, with ultra-soft pseudopotentials, the wavefunction cutoff needed
to get a converged energy is rather low, but to avoid the noise from
the xc-functional evaluation (and from the augmentation charges),
you need a higher density cutoff (by default 4x the wavefunction
cutoff). if you search the mailing archive you'll find that 30-40ry
for the wavefunction cutoff and a factor of 10 for the density cutoff
(i.e. 300-400ry) is a conservative choice.
hope that helps,
axel.
SdG> In general calculated energies are a little noisy (due to insufficient
SdG> scf accuracy and/or
SdG> insufficient accuracy in the integration of the XC functional on the FFT
SdG> real space grid).
SdG> Moreover Energies and forces are slightly inconsistent (due to
SdG> insufficient scf accuracy).
SdG> Hence it is pointless to pretend a convergence in the relaxation below
SdG> this noise level.
SdG> When the history of the relaxation makes no sense the code reduce the
SdG> size of the tipical
SdG> step and restart the history, but if the step is so small that you are
SdG> already digging below
SdG> the noise level this does not help.
SdG>
SdG> By the way forc_conv_thr = 1.0D-5 is an extremey strict threshold.
SdG> default value is 1.0d-3 and usually is alread fine. 1.0d-4 should be
SdG> more than
SdG> enough for any purpouse.
SdG>
SdG> stefano
SdG>
SdG> yukihiro_okuno at fujifilm.co.jp wrote:
SdG>
SdG> >Dear PWscf Users.
SdG> >
SdG> >I'm now working the optimization of PbTiO3
SdG> >
SdG> >But in the process of calculation, my calculation
SdG> >
SdG> >stopped with an error like below
SdG> >
SdG> > CASE: energy_new > energy_old
SdG> >
SdG> > new trust radius= 0.499856 bohr
SdG> >
SdG> > trust_radius < trust_radius_min
SdG> >
SdG> > resetting bfgs history
SdG> >
SdG> >
SdG> >
SdG>
>%%
SdG> > from bfgs : error # 1
SdG> > bfgs history already reset at previous step
SdG> >
SdG>
>%%
SdG> >
SdG> > stopping ...
SdG> >
SdG> >
SdG> >What is wrong and how to treat such an erro?
SdG> >
SdG> >This is my input file
SdG> >
SdG> >&control
SdG> >calculation = 'relax',
SdG> >restart_mode = 'from_scratch',
SdG> >pseudo_dir = '/home/okuno/PWSCF/espresso-3.1.1/pseudo/',
SdG> >outdir = './',
SdG> >forc_conv_thr = 1.0D-5
SdG> > /
SdG> > &system
SdG> >ibrav=6
SdG> >celldm(1)=7.36203352272
SdG> >celldm(3)=1.07
SdG> >nat=5
SdG> >ntyp=3
SdG> >nbnd=25
SdG> >ecutwfc=30.0
SdG> >occupations = 'fixed'
SdG> >degauss=0.00
SdG> > /
SdG> > &electrons
SdG> >conv_thr = 1e-7,
SdG> >mixing_beta=0.3,
SdG> > /
SdG> >&IONS
SdG> > ion_dynamics='bfgs'
SdG> > bfgs_ndim=3
SdG> > pot_extrapolation = "second_order"
SdG> > wfc_extrapolation = "second_order"
SdG> >/
SdG> >ATOMIC_SPECIES
SdG> > Pb207.2 Pb.vdb.UPF
SdG> > Ti47.867Ti.vdb.UPF
SdG> > O 15.9994 O.vdb.UPF
SdG> >ATOMIC_POSITIONS {crystal}
SdG> >Pb 0.0 0.0 0.0
SdG> >Ti 0.5 0.5 0.53402
SdG> >O0.0 0.5 0.61123
SdG> >O0.5 0.0 0.61123
SdG> >O0.5 0.5 0.10391
SdG> >K_POINTS {automatic}
SdG> > 4 4 4 1 1 1
SdG> >
SdG> >
SdG> >___
SdG> >Pw_forum mailing list
SdG> >Pw_forum at pwscf.org
SdG> >http://www.democritos.it/mailman/listinfo/pw_forum
SdG> >
SdG> >
SdG>
SdG> ___
SdG> Pw_forum mailing list
SdG> Pw_forum at pwscf.org
SdG> http://www.democritos.it/mailman/listinfo/pw_forum
SdG>
--
===
Axel Kohlmeye
[Pw_forum] About (7,3) nanowire coordinates
Hi Arijit, The coordinates for the (7,3) Au nanowire are available on the Science website. Check under the supplemental data for the paper. This provides the positions in a_0 units as well as the forces on each atom. If you are unable to access this, let me know and I'll send them your way. Best regards, Derek A Sen writes: > Dear All, > > I would like to generate all of the 85 coordinates of the (7,3) Au chiral > > nanowire using PWScf, which has already been done a long ago by > > Dr. Andrea (Ref. Science, v291,pp290,2001). I would greatly > > appreciate if you could please provide me the input file for this. What would > be > > the input file for the (6,0) nanowire as well? > > With best regards, > > Arijit Derek Stewart, Ph. D. Scientific Computation Associate 250 Duffield Hall Cornell Nanoscale Facility (CNF) Ithaca, NY 14853 stewart (at) cnf.cornell.edu (607) 255-2856
[Pw_forum] q not allowed
hi trying phonon calculation, i used a small grid (331). but using q2r.x, the code has given " q not allowed" in the archive i saw this: >there is a mismatch between what the q2r.x code thinks q-points should be, >and what you provided. what should i do? so i have to forget this grid? how should i choose the grid not to have this error? my case is base-centered tetragonal thanx _ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
[Pw_forum] q not allowed
Hi, > trying phonon calculation, i used a small grid > (331). but using q2r.x, the > code has given " q not allowed" > in the archive i saw this: > >there is a mismatch between what the q2r.x code > thinks q-points should be, > >and what you provided. Sorry, but quite stupid question: are these q-vectros you used in cartesian or wrt basis vescors? As far as I know q2r.x uses q-vectors in cartesian. Besides, it might be that you specified insufficent digits for q-vectors, so they do not coincide with those generated by q2r.x. > what should i do? so i have to forget this grid? how > should i choose the grid not to have this error? > my case is base-centered tetragonal The best way is using of the latest version of QE where you can specify nx,ny,nz in ph.in file so that the program ph.x generates q-vectors and then calculates dynamical matrices for thes q-points. The next step is FFT by means of q2r.x. See example 6. Bests, Eyvaz. > thanx > > _ > Express yourself instantly with MSN Messenger! > Download today it's FREE! > http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/ > > ___ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > No need to miss a message. Get email on-the-go with Yahoo! Mail for Mobile. Get started. http://mobile.yahoo.com/mail
