Dear Matteo, So when we just do the dipolar part, we don't need to care about the k vector, right?
Besides, in order to compare with an experimental spectrum, is it necessary to cut the occupied state below Fermi energy level within our Xspectra calculation ? In that case, we should set "cut_occ_states" = .true. and "ef_r" equal to the fermi energy we got in the scf calculation. Is it? Best regards, Min Wu 2010-10 >From: Matteo Calandra <matteo.calandra at impmc.jussieu.fr> >Reply-To: PWSCF Forum <pw_forum at pwscf.org> >To: pw_forum at pwscf.org >Subject: Re: [Pw_forum] xspectra calculation >Date: Tue, 19 Oct 2010 16:28:30 +0200 > >Dear Min Wu, > > > > >It seems i have found the problem. It's not the problem of the > >xcoordcrys. I set it as .true. and the polarization vectors are >(0,0,1) >and > >(0,1,0). The xray k vector is the default value (1,0,0). > >BTW, can we use the same vector for polarization and xay k moment? > >e.g. Both of them are (1,0,0). Is it OK? > >Of course epsilon and k MUST be ortogonal otherwise what you are doing >is meaningless. If you calculate the dipolar part only then >the k-vector is not used and can take any value. > > > > >The problem i found is that i set the "cut_occ_states" = .true. > >Then it cut all the occupied state that i expected to see. > >When i reset it to .false., i saw the expected peak. > > > >Maybe your ef_r is not in the correct units... Of course you put the >Fermi level in the presence of a core-hole, don't you ? > > >I have another problem, what does the "ef_r" do in the calculation? > >For instance, i got fermi level of -5 eV with scf calculation. > >The i set ef_r= -5/13.6 Ry. Then, in the calculated xspectra data, > >where is > >the Fermi level? It is ajusted to 0 eV, or still is the -5 eV? > > > >zero, the energies are simply shifted. > >M. > >-- >* * * * >Matteo Calandra, Charge de Recherche (CR1) >Institut de Min?ralogie et de Physique des Milieux Condens?s de Paris >Universit? Pierre et Marie Curie, tour 16, case 115 >4 Place Jussieu, 75252 Paris Cedex 05 France >Tel: +33-1-44 27 52 16 Fax: +33-1-44 27 37 85 >http://www.impmc.jussieu.fr/~calandra >_______________________________________________ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum >
