Dear Huang: Thanks very much for your help:) LO-TO splitting always exists in Brillouin zone, but two points are worth > noting: > I do not think so. I do not find any LO-TO splitting at the X and R point of Brillouin zone of cubic. Because I use finite difference method, I do not know LO-TO splitting persists at other part.
> (2) only cubic crystals has LO and TO braches. > The LO-TO splitting exists also in uniaxial crystal(direction dispersion in Raman). -- ____________________________________ Hui Wang School of physics, Fudan University, Shanghai, China -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110429/245b4fc0/attachment.htm
