Dear Hai-Ping Nick is right, DCC for partial periodicity is not in the cvs version of the code yet. The main issue is not the "whichbc" parameter that you've checked in the Multigrid directory. The way that the true potential is calculated?(add_boundary.f90)?and?Poisson equation that?is?solved should be modified accordingly (add_dcc_field.f90). Regards, ? Emine Kucukbenli, grad student, SISSA, Italy.
--- On Thu, 2/19/09, lan haiping <lanhaiping at gmail.com> wrote: From: lan haiping <[email protected]> Subject: Re: [Pw_forum] DCC correction to electrostatic potential To: "PWSCF Forum" <pw_forum at pwscf.org> Date: Thursday, February 19, 2009, 4:12 AM Dear Nick, Thanks.? Therefore, My problem is just due to wrong BC handling by QE. I found the settings for boundary conditions at $QE/Multigrid, and just thought it should be OK for all possible aperiodic situations. Would you mind to tell me which subroutine in $QE/EE accounts for boundary settings ? Regards, Hai-Ping On Thu, Feb 19, 2009 at 1:20 AM, Nicholas E. Singh-Miller <nedward at mit.edu> wrote: Dear Hai-Ping, I am looking at espresso-4.1CVS. Looking at the subroutines in EE/, it looks like the DCC correction is currently only coded for isolated systems -- in which case the calculataion of BCs for a CNT would cut through the charge density. (but I could be missing something). Regads, Nick On Wed, 18 Feb 2009, lan haiping wrote: > Dear All, > > ?I did test calculations on DCC correction implemented in CVS version. > I came to ?problems when i examine the results of electrostatic potential. > Would you please give me some hints ? > My test calculation is a CNT (10,10) ?system, ?and the setting for > DCC correction is > ? ? ? ?which_compensation ='dcc', > ? ? ? ?ecutcoarse = 100.0, > ? ? ? ?n_charge_compensation= 5, > ? ? ? ?nlev = 4, > ? ? ? ?whichbc(1)= 0, whichbc(2)=0, > ? ? ? ?whichbc(3)=1, > But the final fermi energy i obtained is -3.99 eV, which is not consistent > with > previous report on workfunction of CNTs(about 4.6 eV ). > > Best, > Hai-Ping > > > ***************************************** Nicholas E. Singh-Miller Ph.D. Candidate Prof. Marzari Group (quasiamore.mit.edu) Materials Science and Engineering Massachusetts Institute of Technology 13-4066 (617)324-0372 ***************************************** _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -- Hai-Ping Lan Department of Electronics , Peking University , Bejing, 100871 lanhaiping at gmail.com, hplan at pku.edu.cn _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090219/622f6901/attachment.htm
