Giuseppe, thanks very much for the experience you shared, it's really valuable, ^_^.
????????????????????: >From: Giuseppe Mattioli <giuseppe.mattioli at mlib.ism.cnr.it> >Reply-To: PWSCF Forum <pw_forum at pwscf.org> >To: Jun Dai <jdai3 at mail.ustc.edu.cn>, PWSCF Forum <pw_forum at pwscf.org> >Subject: Re: [Pw_forum] V pseudopotential >Date:Tue, 7 Jul 2009 12:07:16 +0200 > >I don't have any V normcons pseudo for you, but I still would share some >results. I'm trying to study a 6 atom rutile TiO2 cell with the pbe0 hybrid >functional (48 electrons, convergence achieved by using a k444 grid in the >case of the pbe xc). Honestly, I didn't understand how to deal with the q grid >in the case of periodic systems (the nqx variables. In the case of molecules I >managed to have fine results by using the gamma point and a 111 q grid), then >I tried different grids (q111, q222, q444). The q111 case requires reasonable >resources but doesn't provide reliable results. The q222 case is already very >expensive and the achieved results are still not very good. I regard a lattice >parameter optimization in this case as a "bath of blood" (dunno if you say >something similar...:-)). The q444 case... don't do it, please. I suspect that >V oxide cells are larger, so work harder on the DFT+U calculations... > >However, look (more than two seconds) at the /yourespresso/atomic_doc/ >directory. It should be really easy to generate a norm conserving V >pseudopotential. Then, make several tests in order to say if your >pseudopotential is a good one (and this is a little more difficult). It is >indeed one of the more instructive tasks if you want understand (on a >practical basis) how to perform reliable calculations. > >Yours >Giuseppe > > >On Monday 06 July 2009 18:41:33 Jun Dai wrote: >> Dear all, >> I want to have a try of the hybrid functional implemented in Q-E for a >> vanadium oxide system, since the LDA+U failed to give reasonable results, >> and the ultrasoft pp seems not supported yet, so can someone share a copy >> of norm-conserving V pseudopotential with me? Thanks in advance. >> >> >> >> >> ------------------------------ >> Best regards, >> Jun Dai >> >> ============================================================= >> J. Dai >> Ph.D. Candidate, >> Hefei National Laboratory For Physical Sciences at the Microscale, >> University of Science and Technology of China, >> Hefei, Anhui, 230026, >> People's Republic of China >> Tel.: 86-551-3606428 >> Fax.: 86-551-3602969 >> E-mail: jdai3 at mail.ustc.edu.cn >> ============================================================= >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum > >-- >******************************************************** >- Article premier - Les hommes naissent et demeurent >libres et ?gaux en droits. Les distinctions sociales >ne peuvent ?tre fond?es que sur l'utilit? commune >- Article 2 - Le but de toute association politique >est la conservation des droits naturels et >imprescriptibles de l'homme. Ces droits sont la libert?, >la propri?t?, la s?ret? et la r?sistance ? l'oppression. >******************************************************** > > Giuseppe Mattioli > CNR - ISTITUTO DI STRUTTURA DELLA MATERIA > v. Salaria Km 29,300 - C.P. 10 > I 00016 - Monterotondo Stazione (RM) > Tel + 39 06 90672836 - Fax +39 06 90672316 > E-mail: <giuseppe.mattioli at ism.cnr.it> >_______________________________________________ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum
