Thank you Matteo, this should be doable, and thank you for providing the tutorial, even if it is a bit rough on the edges it was very useful.
On Monday, September 5, 2016 12:11:42 AM CEST Matteo Cococcioni wrote: > Hi Lorenzo, > > the two tutorial should be quite equivalent, although the one Federico > found is more recent and probably I updated some details. > > Regarding your questions: as far as I understand you are only interested in > U on one specific atomic species of your materials. You could do that by > doing two perturbations: one on the atom you are interested in, the second > on all the other atoms (which you treat as a "macro-atom") at the same > time. Of course the occupation of this second "extended atom" is the sum of > the occupations of the atoms it is composed by. you then construct a 2x2 > response matrix that, once inverted, should give you the U you are looking > for (throwing away the one for the "macro-atom"). > This only limits the number of perturbation but still requires a supercell > of sufficiently large size. > > We are working on a way to make the whole procedure more efficient, through > automatizing the linear-response, but the code is not ready yet. > > Best, > > Matteo > > On Fri, Sep 2, 2016 at 5:55 PM, Lorenzo Paulatto < > > [email protected]> wrote: > > Hello, > > I have a question about how to compute the abinitio U, I'm following the > > online Santa Barbara 2009 tutorial (and trying to use the script therein) > > and > > PRB 71, 35105 (2005). > > > > I have a system that is not very large but quite heavy to compute, and > > have > > several atomic species (3 at first, then 4) but only one is problematic, > > as it > > is could be Cerium or other Lanthanoids. > > > > It would be quite anoying and very cpu time consuming for me to properly* > > compute U by finite response for all the species, but I'm not sure that > > 1. it is possible with the available toolchain > > 2. it makes sense > > > > Also, if somebody (e.g. Matteo) has some more recent and/or more user > > friendly > > code to compute dalpha/dn I'm a taker. > > > > thank you for your help! > > > > *) by properly I mean take care that it is converged with the supercell > > size > > > > -- > > Dr. Lorenzo Paulatto > > IdR @ IMPMC -- CNRS & Université Paris 6 > > +33 (0)1 44 275 084 / skype: paulatz > > http://www.impmc.upmc.fr/~paulatto/ > > 23-24/4é16 Boîte courrier 115, > > 4 place Jussieu 75252 Paris Cédex 05 > > > > _______________________________________________ > > Pw_forum mailing list > > [email protected] > > http://pwscf.org/mailman/listinfo/pw_forum -- Dr. Lorenzo Paulatto IdR @ IMPMC -- CNRS & Université Paris 6 phone: +33 (0)1 44275 084 / skype: paulatz www: http://www-int.impmc.upmc.fr/~paulatto/ mail: 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
