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<DIV>Dear Wang Di: <BR> Are you using Norm-Conserving pseudopotentials? If you are, please increase the ecutwfc to be about 50 Ry or larger, and the density of the k mesh should be high enough (by tests). This is because the accuracy of the calculation of stress is much dependent on the completeness of the plane wave basis set.</DIV>
<DIV> In addition, the forc_conv_thr=1.0d-4 already be great (usually 1.0d-3 is used), smaller thresholds (e.g. 1.0d-6) won't make any difference and only waste much of your invaluable time. And I am very curious about why did you use "<FONT color=#444444>dipfield = .true.</FONT>" for your 3D-periodic crystalline system?</DIV>
<DIV> </DIV>
<DIV>PS: we are working at the same island (science island), but two institutes, calculating in the same super-computer. I am very glad to meet you on the same Forum :)</DIV>
<DIV> </DIV>
<DIV>Best Wishes!</DIV>
<DIV> </DIV>
<DIV>Yours Sincerely</DIV>
<DIV>L. F. Huang</DIV>
<DIV> </DIV>
<DIV> <BR></FONT><FONT color=#444444>> Date: Mon, 20 Sep 2010 14:07:30 +0800 <BR></FONT><FONT color=#444444>> From: Wang Di <BR></FONT><FONT color=#444444>> Subject: [Pw_forum] question about the stress in relax process <BR></FONT><FONT color=#444444>> To: PWSCF Forum <BR></FONT><FONT color=#444444>> Message-ID: <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> Content-Type: text/plain; charset="iso-8859-1" <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> Dear all <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> I perform the relax calculate to the crystal structure. After 11 step bfgs, <BR></FONT><FONT color=#444444>> the total force and total scf correction had reach to the criterion, <BR></FONT><FONT color=#444444>> however, the total stress was so big P=-3443.87. I have no idea about deal <BR></FONT><FONT color=#444444>> with the case, could anyone give some advices? Thanks in advance. <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> the input file <BR></FONT><FONT color=#444444>> : &CONTROL <BR></FONT><FONT color=#444444>> calculation = 'scf' , <BR></FONT><FONT color=#444444>> restart_mode = 'from_scratch' , <BR></FONT><FONT color=#444444>> wf_collect = .true. , <BR></FONT><FONT color=#444444>> outdir = '/lustre/AIOFM/gxgu/workLCAF/5/temp/' , <BR></FONT><FONT color=#444444>> wfcdir = '/lustre/AIOFM/gxgu/workLCAF/5/wftemp/' , <BR></FONT><FONT color=#444444>> pseudo_dir = '/home/AIOFM/gxgu/work/NCPP/' , <BR></FONT><FONT color=#444444>> prefix = 'LCAF' , <BR></FONT><FONT color=#444444>> etot_conv_thr = 1.0D-7 , <BR></FONT><FONT color=#444444>> forc_conv_thr = 1.0D-6 , <BR></FONT><FONT color=#444444>> nstep = 100 , <BR></FONT><FONT color=#444444>> tstress = .true. , <BR></FONT><FONT color=#444444>> tprnfor = .true. , <BR></FONT><FONT color=#444444>> dipfield = .true. , <BR></FONT><FONT color=#444444>> / <BR></FONT><FONT color=#444444>> &SYSTEM <BR></FONT><FONT color=#444444>> ibrav = 4, <BR></FONT><FONT color=#444444>> celldm(1) = 9.42432151, <BR></FONT><FONT color=#444444>> celldm(3) = 1.94804220, <BR></FONT><FONT color=#444444>> nat = 18, <BR></FONT><FONT color=#444444>> ntyp = 4, <BR></FONT><FONT color=#444444>> ecutwfc = 30 , <BR></FONT><FONT color=#444444>> ecutrho = 120 , <BR></FONT><FONT color=#444444>> nosym = .false. , <BR></FONT><FONT color=#444444>> / <BR></FONT><FONT color=#444444>> &ELECTRONS <BR></FONT><FONT color=#444444>> electron_maxstep = 100, <BR></FONT><FONT color=#444444>> conv_thr = 1.0D-10 , <BR></FONT><FONT color=#444444>> / <BR></FONT><FONT color=#444444>> ATOMIC_SPECIES <BR></FONT><FONT color=#444444>> Li 6.94100 03-Li.LDA.fhi.UPF <BR></FONT><FONT color=#444444>> Al 26.98154 13-Al.LDA.fhi.UPF <BR></FONT><FONT color=#444444>> Ca 40.07800 20-Ca.LDA.fhi.UPF <BR></FONT><FONT color=#444444>> F 18.99840 09-F.LDA.fhi.UPF <BR></FONT><FONT color=#444444>> ATOMIC_POSITIONS crystal <BR></FONT><FONT color=#444444>> Li 0.333333333 0.666666667 0.250000000 <BR></FONT><FONT color=#444444>> Li -0.333333333 -0.666666667 -0.250000000 <BR></FONT><FONT color=#444444>> F 0.389997 0.045970 0.148326 <BR></FONT><FONT color=#444444>> F -0.045970 0.344027 0.148326 <BR></FONT><FONT color=#444444>> F -0.344027 -0.389997 0.148326 <BR></FONT><FONT color=#444444>> F -0.045970 -0.389997 0.351674 <BR></FONT><FONT color=#444444>> F -0.344027 0.045970 0.351674 <BR></FONT><FONT color=#444444>> F 0.389997 0.344027 0.351674 <BR></FONT><FONT color=#444444>> F -0.389997 -0.045970 -0.148326 <BR></FONT><FONT color=#444444>> F 0.045970 -0.344027 -0.148326 <BR></FONT><FONT color=#444444>> F 0.344027 0.389997 -0.148326 <BR></FONT><FONT color=#444444>> F 0.045970 0.389997 0.648326 <BR></FONT><FONT color=#444444>> F 0.344027 -0.045970 0.648326 <BR></FONT><FONT color=#444444>> F -0.389997 -0.344027 0.648326 <BR></FONT><FONT color=#444444>> Al 0.666666667 0.333333333 0.250000000 <BR></FONT><FONT color=#444444>> Al -0.666666667 -0.333333333 -0.250000000 <BR></FONT><FONT color=#444444>> Ca 0.000000000 0.000000000 0.000000000 <BR></FONT><FONT color=#444444>> Ca 0.000000000 0.000000000 0.500000000 <BR></FONT><FONT color=#444444>> K_POINTS automatic <BR></FONT><FONT color=#444444>> 16 16 16 0 0 0 <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> best regart <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> Wang Di <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> -- <BR></FONT><FONT color=#444444>> ----------------------------------------------------------------- <BR></FONT><FONT color=#444444>> *Wang Di** <BR></FONT><FONT color=#444444>> The Crystal Lab,* <BR></FONT><FONT color=#444444>> *AnHui Institute of Optics and Fine Mechanics, *** <BR></FONT><FONT color=#444444>> *Chinese Academy of Sciences,** <BR></FONT><FONT color=#444444>> No350. , Shushanhu Road, Hefei, 230031, China**, <BR></FONT><FONT color=#444444>> E-mail: didi5158 @gmail.ocm** ,* <BR></FONT><FONT color=#444444>> ----------------------------------------------------------------- <BR></FONT><FONT color=#444444>> -------------- next part -------------- <BR></FONT><FONT color=#444444>> An HTML attachment was scrubbed... <BR></FONT><FONT color=#444444>> URL: <A href="http://www.democritos.it/pipermail/pw_forum/attachments/20100920/df91893a/attachment-0001.htm" target=_blank>http://www.democritos.it/pipermail/pw_forum/attachments/20100920/df91893a/attachment-0001.htm</A< FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> ------------------------------ <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> _______________________________________________ <BR></FONT><FONT color=#444444>> Pw_forum mailing list <BR></FONT><FONT color=#444444>> <A href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</A> <BR></FONT><FONT color=#444444>> <A href="http://www.democritos.it/mailman/listinfo/pw_forum" target=_blank>http://www.democritos.it/mailman/listinfo/pw_forum</A> <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> <BR></FONT><FONT color=#444444>> End of Pw_forum Digest, Vol 39, Issue 31 <BR></FONT><FONT color=#444444>> **************************************** <BR></FONT><FONT color=#444444>> <BR><BR><BR>------ <BR>====================================================================== <BR>L.F.Huang(黄良锋) DFT and phonon physics <BR>====================================================================== <BR>Add: Research Laboratory for Computational Materials Sciences, <BR>Instutue of Solid State Physics,the Chinese Academy of Sciences, <BR>P.O.Box 1129, Hefei 230031, P.R.China <BR>Tel: 86-551-5591464-326(office) <BR>Fax: 86-551-5591434 <BR>Our group: <A href="http://theory.issp.ac.cn/" target=_blank>http://theory.issp.ac.cn</A> <BR>====================================================================== <BR></DIV></FONT></FONT></div>
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