I think that with meta-GGA what is written in the first two fields is just ignored
Paolo On Fri, May 4, 2018 at 5:39 PM, José C. Conesa <[email protected]> wrote: > Dear QE developers, > > I wish to use in Quantum Espresso the tb09 potential-only meta-GGA > functional (from Tran & Blaha, PRL 102, 2009, 226401) which is available in > libxc. I downloaded the libxc library and compiled successfully qe-6.2.1 > with it. Then I see in Modules/funct.f90 that the instruction to use this > functional is equivalent to specifying > > input_dft="sla+pw+tb09+tb09" > > But as far as I know, the tb09 functional gives only the exchange part, > and gives it in full (not as a correction to another expression for the > exchange), while sla is a LDA exchange form (and pw a LDA correlation > form). Should one conclude that exchange is being introduced twice? And, is > a gradient correction to the correlation term not included? From these > considerations, I would have thought that using something like > > input_dft="pw+pbc+tb09+tb09" > > (where I hope that the tb09 exchange functional is not included twice), > i.e. the correlation part of PBE plus the Tran & Blaha exchange functional, > would be the proper way to proceed. > > Can you please comment on this? > > I also would add that it would be good to be able to adjust the A and B > parameters of the tb09 functional. This has been proposed in (Koller, Tran > & Blaha, PRB 85, 2012, 155109) to obtain better bandgaps in certain > families of semiconductors. > > All the best, > > -- > José C. Conesa > Instituto de Catálisis y Petroleoquímica, CSIC > Marie Curie 2, Cantoblanco > 28049 Madrid, Spain > Tel. (+34)915854766 > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > Libre > de virus. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> > <#m_5099655024476259839_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> > > _______________________________________________ > users mailing list > [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users > -- 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
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