Dear Reza Ebraahimi: I have a question. Does the existence of a gap in the high-energy region of > the phonon DOS means ionicity of the crystal (splitting of the TO and > LO-like phonons)? The higher the gap, means the more ionicity? > I do not think so. You can see the "one-dimensional diatomic chain model" as given in <Dynamic Theory of Crystal Lattices> written by Max Born and Kun Huang.
____________________________________ Hui Wang School of physics, Nankai University, Tianjin, China -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20091024/9f20ea2f/attachment.htm
