Dear Prof. Tran: thank you very much for your reply. Since I am not accessible to the paper at this moment, I will try to understand tomorrow. My, hopefully last this time, question: then, does hybrid functional (HSE, kinds of) allow us to take vacuum into consideration in the calculation?
Thank you so much again. Best regards, Mat -------- Original Message -------- Subject: Re: [Wien] volume optimization From: t...@theochem.tuwien.ac.at To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at> Date: 2011/05/08 19:03 > mBJ should be used only for bulk solids (no vacuum). If there is > vacuum, then the calculation of the average of (grad rho)/rho in the > unit cell [see Eq. (3) in PRL, 102, 226401 (2009)] does not make any > sense. A solution would be to fix the value of c [Eq. (3)], but this > requires the modification of the subroutine vxclm2.f. > > In case you want PBE-GGA total energy instead of LDA, you have to replace > > exu=2.d0*(exupls + eclsd) > exd=2.d0*(exdnls + eclsd) > > by > > exu=2.d0*(exuppb + ecpbe) > exd=2.d0*(exdnpb + ecpbe) > > in vxclm2.f (below IGRAD .EQ. 28). > > > On Sun, 8 May 2011, Matthew Stream wrote: > >> Dear Prof. Tran: >> thank you for your prompt reply. >> >>> What is not possible, is to use forces for >>> the optimization of internal parameters. >> >> I got it. >> >>> What do you mean by QW, QWR, QD? >> QW :Quantum Well, >> QWR:Quantum Wire, and >> QD :Quantum Dot, >> respectively. >> Is the similar procedure you suggested applicable to these structures, >> if I use super cells appropriately for them? >> >> Thank you in advance. >> >> Mat >> >> -------- Original Message -------- >> Subject: Re: [Wien] volume optimization >> From: tran at theochem.tuwien.ac.at >> To: A Mailing list for WIEN2k users<wien at zeus.theochem.tuwien.ac.at> >> Date: 2011/05/08 16:28 >> >>> Hello, >>> >>> When you use mBJ (number 28 in case.in0), the total energy is calculated >>> with LDA (i.e., the mBJ orbitals and electron density are plugged into >>> the LDA functional), and you can use this total energy for calculation of >>> energy vs. volume of unit cell. What is not possible, is to use forces for >>> the optimization of internal parameters. What do you mean by QW, QWR, QD? >>> >>> Hybrid functionals similar to HSE are in WIEN2k, but I don't know when it >>> will be released into the distributed WIEN2k version: >>> http://arxiv.org/abs/1103.4466 >>> >>> F. Tran >>> >>> On Sun, 8 May 2011, Matthew Stream wrote: >>> >>>> Dear WIEN2k users and Prof. Blaha: >>>> >>>> Could you teach me if there's a way to calculate the Energy vs. volume >>>> curve for bulk, QW, QWR, QD (whatever, e.g. GaAs bulk crystal) with >>>> realistic band gap ( comparable to the experimental value)? >>>> >>>> As far as I know, mBJ is only a potential which is not applicable to the >>>> optimization, while HSE functional is not yet introduced into WIEN2k. >>>> >>>> Kind regards, >>>> Mat >>>> _______________________________________________ >>>> Wien mailing list >>>> Wien at zeus.theochem.tuwien.ac.at >>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien >>>>