<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>Hi</DIV>
<DIV>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?</DIV>
<DIV>Thank You for any reply</DIV>
<DIV> </DIV>
<DIV>Reza Ebraahimi- Graduate Student</DIV>
<DIV>Tehran University </DIV><!-- cg1.c902.mail.ac4.yahoo.com compressed/chunked Sat Oct 24 05:34:13 PDT 2009 --></div><br>
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