>Dear Matteo, >So when we just do the dipolar part, we don't need to care about the >k vector, right?
yes, it is not used. >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? Yes. However if you have a small gap insulator, introduction of a core-hole can lead to a metallic system (close the gap). In this case it is not clear where to cut. Actually in this case the static core-hole approximation is probably incorrect. For metals it is even worst. M. Best regards, Min Wu 2010-10 -- * * * * 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