On Thu, 19 Apr 2007, Yurko Natanzon wrote: | Well, this works for TiO2, but when I tried to do it with SiO2, I've got: | | then oxygen has positive ionic charge (6-5.987), and silicon has | negative (4-4.026). Does it make any sense??
Dear Yurko: they have no more sense than "ionic charge" in general; such numbers are totally dependent on their definition (in the case given - on your choice of basis functions), even more so as you deal with covalent bond. Similarly funny numbers may occur e.g. in LMTO-ASA (charges come from integration over overlapping atomic spheres). It doesn't mean that your calculation is wrong, though. Just, better not to show these numbers to chemists... Best regards Andrei Postnikov +-- Dr. Andrei Postnikov ---- Tel. +33-387315873 ----- mobile +33-666784053 ---+ | Paul Verlaine University - Institute de Physique Electronique et Chimie, | | Laboratoire de Physique des Milieux Denses, 1 Bd Arago, F-57078 Metz, France | +-- [EMAIL PROTECTED] ------ http://www.home.uni-osnabrueck.de/apostnik/ --+
