Thank you so much for your help. It really cleared things up. ---------------------------------------------------------------------------------------------------------------- Joshua D. Davis
Graduate Assistant Department of Chemistry Michigan State University East Lansing, MI 48824 ----------------------------------------------------------------------------------------------------------------- On Tue, Mar 3, 2015 at 3:40 AM, Matteo Cococcioni <[email protected]> wrote: > Dear Joshua > > On Mon, Mar 2, 2015 at 4:27 PM, Joshua Davis <[email protected]> > wrote: > >> Dear QE Users >> >> I want to know how to calculate U based on linear response >> <http://journals.aps.org/prb/abstract/10.1103/PhysRevB.71.035105>, but >> I am having trouble understanding what occupation values to use from a >> calculation for a response matrix. >> >> I have fallowed the tutorials >> >> >> http://media.quantum-espresso.org/santa_barbara_2009_07/slides-exercices/Handson_ldau.pdf >> >> and >> >> http://hjklol.mit.edu/content/calculating-hubbard-u >> >> >> > you have to use the trace of the occupation matrix. > > > >> Do I use the Trace of the d-electron occupation matrix (like in the first >> link) or am I to use sum of all the elements of the matrix (like in the >> second link)? >> >> Secondly when calculating U, if the atoms that require a U are not very >> close to each other, can you get away with not calculating the off-diagonal >> response matrix elements and just invert the diagonal response matrix >> elements directly? >> > > > I guess it depend on the system you are considering. just try in one case > and see how results compare. > > Matteo > > > >> >> I am using QE 5.1. >> Thanks for any help >> >> ---------------------------------------------------------------------------------------------------------------- >> Joshua D. Davis >> >> Graduate Assistant >> Department of Chemistry >> Michigan State University >> >> East Lansing, MI 48824 >> >> ----------------------------------------------------------------------------------------------------------------- >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
_______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
