FYI. There is NO truncation on the mailing list, we got all what you sent. You gmail did it. Click Show Quote Text for full email.
-------------------------------------------------- Duy Le PhD Student Department of Physics University of Central Florida. "Men don't need hand to do things" On Tue, Nov 9, 2010 at 9:02 PM, Brad Malone <brad.malone at gmail.com> wrote: > No idea why it is being truncated, so this time I'll start the email after > the error message > --------------- > From the forums: > > http://www.democritos.it/pipermail/pw_forum/2008-September/010123.html > http://www.democritos.it/pipermail/pw_forum/2010-February.txt > > I understand that the third derivatives were never implemented and > that only the LDA part was calculated, for the Perdew Zunger > parameterization. Is this third derivative the third derivative that > is mentioned in the routine PH/raman_mat.f90 (i.e, the third > derivative of the energy with respect to the atomic displacements and > with respect to two electric fields, as described in Lazzeri and > Mauri, PRL 90,036401)? > > I am interested in getting a feel for what would be needed to > implement the third derivatives with GGA into the code, as well as > what sort of errors one might expect when using the third-order term > as currently coded with LDA pseudopotentials (comments in the forums > have hinted that the errors are likely small). The shift in the Raman > spectra for cd-Si is pretty minor when using a GGA pseudo compared to > that of an LDA calculation, but I wanted to be able to quantify the > error better for other systems where comparing the GGA raman spectra > to one calculated within LDA was not possible (e.g., when the system > doesn't exhibit a gap in LDA). > > Thanks for the help! > > Best, > Brad > UC Berkeley > > > On Tue, Nov 9, 2010 at 5:59 PM, Brad Malone <brad.malone at gmail.com> wrote: > >> It appears that my last email was severely truncated on the mailing list >> (even though it looks fine in my outbox). Below is what is should have been: >> ----------------------- >> Hi, I am seeking more information on the error >> >> > from phq_setup : error # 1 >> > third order derivatives not implemented with GGA >> >> From the forums: >> >> http://www.democritos.it/pipermail/pw_forum/2008-September/010123.html >> http://www.democritos.it/pipermail/pw_forum/2010-February.txt >> >> I understand that the third derivatives were never implemented and >> that only the LDA part was calculated, for the Perdew Zunger >> parameterization. Is this third derivative the third derivative that >> is mentioned in the routine PH/raman_mat.f90 (i.e, the third >> derivative of the energy with respect to the atomic displacements and >> with respect to two electric fields, as described in Lazzeri and >> Mauri, PRL 90,036401)? >> >> I am interested in getting a feel for what would be needed to >> implement the third derivatives with GGA into the code, as well as >> what sort of errors one might expect when using the third-order term >> as currently coded with LDA pseudopotentials (comments in the forums >> have hinted that the errors are likely small). The shift in the Raman >> spectra for cd-Si is pretty minor when using a GGA pseudo compared to >> that of an LDA calculation, but I wanted to be able to quantify the >> error better for other systems where comparing the GGA raman spectra >> to one calculated within LDA was not possible (e.g., when the system >> doesn't exhibit a gap in LDA). >> >> Thanks for the help! >> >> Best, >> Brad >> UC Berkeley >> >> On Tue, Nov 9, 2010 at 5:00 PM, Brad Malone <brad.malone at gmail.com>wrote: >> >>> Hi, I am seeking more information on the error >>> >>> > from phq_setup : error # 1 >>> > third order derivatives not implemented with GGA >>> >>> From the forums: >>> >>> http://www.democritos.it/pipermail/pw_forum/2008-September/010123.html >>> http://www.democritos.it/pipermail/pw_forum/2010-February.txt >>> >>> I understand that the third derivatives were never implemented and >>> that only the LDA part was calculated, for the Perdew Zunger >>> parameterization. Is this third derivative the third derivative that >>> is mentioned in the routine PH/raman_mat.f90 (i.e, the third >>> derivative of the energy with respect to the atomic displacements and >>> with respect to two electric fields, as described in Lazzeri and >>> Mauri, PRL 90,036401)? >>> >>> I am interested in getting a feel for what would be needed to >>> implement the third derivatives with GGA into the code, as well as >>> what sort of errors one might expect when using the third-order term >>> as currently coded with LDA pseudopotentials (comments in the forums >>> have hinted that the errors are likely small). The shift in the Raman >>> spectra for cd-Si is pretty minor when using a GGA pseudo compared to >>> that of an LDA calculation, but I wanted to be able to quantify the >>> error better for other systems where comparing the GGA raman spectra >>> to one calculated within LDA was not possible (e.g., when the system >>> doesn't exhibit a gap in LDA). >>> >>> Thanks for the help! >>> >>> Best, >>> Brad >>> UC Berkeley >>> >> >> > > _______________________________________________ > 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/20101109/b6acd7dc/attachment.htm
