Dear Stefano de Gironcoli Thanks a lot for your instructive and informative comments.
-- Sincerely Yours David G. JCU > In a pseudopotential calculation core electrons are not there so if you > want to "see" the core electrons you need to do an all-electron > calculation or a PAW calculation where the total charge is reconstructed. > If you are interested in knowing a total atomic charge this is easy... > just add to the valence electron charge the number of (completely > filled) core electrons, change sign and add the nuclear charge.. > notice however that the decomposition of a charge distribution in > atomic contribution is a somewhat ill defined procedure and Lowdin > procedure is just one possibility, so do not attach too much > significance to minor changes from system to system... > > Something that can be useful to identify bonding in your system can be > the analysis of the projected density of states on atomic levels of > nearest-neighbor atoms. It is sometime possible to see peaks occurring > in the same energy range for the two atoms that signal that electronic > states in that energy range are shared between the two atoms as one > expect in a covalent bond. > > Hope it helps. > > Stefano de Gironcoli > David Grifith wrote: >* Dear Heather *>* *>* Thanks for your comments. I think that this type of charge (Lowdin) which is *>* nearly the number of valence electrons can not speak about the details of *>* the system. *>* Some electrons are bonding and also, the effect of the core (core electron + *>* nucleus ) is not negligible. I want to compare the real charge of two atoms *>* in my system with each other not their valence electrons. I appreciate your *>* help in advance. * -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20101211/123a3b5d/attachment-0001.htm
