Dear Sylwia The idea of the Force theorem (implemented by Alexander Smogunox in QE) is more or less to treat the SOC as a small perturbation. The total energy (or rather its variation) is given by the band energy term after a single diagonalization (with SOC but starting from scf potential without SOC) This is explained in: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.90.205409
In addition this band energy term can be decomposed in atomic/orbital contributions as also explained in https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.247203 Best wishes Cyrille ======================== Cyrille Barreteau CEA Saclay, IRAMIS, SPEC Bat. 771 91191 Gif sur Yvette Cedex, FRANCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +33 1 69 08 38 56 /+33 6 47 53 66 52 (mobile) email: [email protected] Web: http://iramis.cea.fr/Pisp/cyrille.barreteau/ ======================== ________________________________ De : [email protected] [[email protected]] de la part de Sylwia Golab [[email protected]] Envoyé : mardi 13 février 2018 17:14 À : [email protected] Objet : Re: [Pw_forum] Restart from previous run Dear Mr Paulatto and Mr Gianozzi, thank you for your replies. In example with Force Theorem there are fully-relativistic nscf calculations based on scalar-relativistic scf calculations. As far as I know, scf potential should be also calculated with SOC to get correct potential. Am I wrong? I tried to use the 'filepot' parameter and it seems to work (e.g. I did not get errors), but with this parameter the scf cycle was only of 1 iteration shorter than "normal" scf cycle with SOC. Best wishes, Sylwia ------------------------------ Message: 7 Date: Wed, 7 Feb 2018 21:58:01 +0100 From: Paolo Giannozzi <[email protected]> Subject: Re: [Pw_forum] Restart from previous run To: PWSCF Forum <[email protected]> Message-ID: <CAPMgbCvNdJMJwkcw85==5yrn3nj_VUNpsK7V-gVHKK1=tne...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" On Wed, Feb 7, 2018 at 8:13 PM, Lorenzo Paulatto <[email protected]> wrote: > 1) when one want to include SOC. It would be great if one could start > > from potential already calculated without SOC instead of potential of > > free atoms. Is it possible just by mode 'restart'? > > no > It might be actually possible. Something similar is used in one of the examples (PP/examples/ForceTheorem_example) > but increasing the number of k-points may increase the number of plane > waves, which would break reading the potential in G-space. > actually it is the charge density that is read. The G-vector grid for the charge density should not depend upon the number of k-points. If I remember correctly the new file format writes in G-space, the old one > used real space, but I'm not 100% sure. > correct Paolo -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20180207/da192696/attachment-0001.html
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