Dear Professor Fratesi, Thank you so much for your helpful and instructive comments. Sincerely,
------------------------------------------- Yavar Taghipour Azar PhD Student Physics Group, AEOI Tehran-Iran Email: ytaghipour at aeoi.org.ir Phone: +98 (0) 21 82064556 ----------------------------------------------------------- -----Original Message----- From: Guido Fratesi <[email protected]> To: pw_forum at pwscf.org Date: Tue, 03 Jul 2012 09:40:47 +0200 Subject: [***SPAM*** Score/Req: 10.00/5.0] Re: [Pw_forum] [***SPAM*** Score/Req: 10.00/5.0] Re: [***SPAM*** Score/Req: 10.00/5.0] Re: (no subject) > But when we divide the unit cell into 2 parts > and we use projwfc.x for calculation of local dos, the sum of two local > dos columns is smaller than total dos. You are probably using USPP and missing the augmentation charge contribution. > I will be very grateful ifyou can give me a suggestion or reference for > more information about the origin of the difference between result of > local dos and summation of projected dos in the same volume. These are two different concepts (below, psi_nk=bands; phi=atomic wfc): PDOS_nlm: sum_nk weight(k) occupation(n,k) | <psi_n(k)|phi_nlm> |^2 LDOS_vol: sum_nk weight(k) occupation(n,k) \int_vol d3r |psi_n(k)(r)|^2 Try to figure out them, there's no reason why they would be the same. There's no "same volume" for PDOS and LDOS. Only the sum of all PDOS_nlm should equal the total DOS. Idem, the LDOS in the cell volume should be the total DOS but the augmentation contribution to |psi(r)| was not implemented. > PS: I want to compare total and adsorbate-projected density of states, > which one is correct method; summation over all projected dos on > adsorbate atoms or calculation of local dos for the box which contains > all of the atoms of adsorbate? Keeping in mind that arbitrariness is present in both methods, and qualitative questions can be answered, I would use the PDOS. Try answer the questions: "what is THE box which contains all of the atoms of the adsorbate?" Can you? Or worse... "Do electrons belong to this atom?" Guido PS there's extensive literature on the subject of partitioning charge: very recently, http://link.aps.org/doi/10.1103/PhysRevLett.108.166403 -- Guido Fratesi Dipartimento di Scienza dei Materiali Universita` degli Studi di Milano-Bicocca via Cozzi 53, 20125 Milano, Italy _______________________________________________ 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/20120703/197a4280/attachment.htm
