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<div>Dear Wang:
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<BR>
</FONT><FONT color=#444444>> LO-TO splitting always exists in Brillouin zone, but two points are worth
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</FONT><FONT color=#444444>> </FONT><FONT color=#444444>> noting:
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</FONT><FONT color=#444444>> >
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</FONT><FONT color=#444444>> I do not think so. I do not find any LO-TO splitting at the X and R point of
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</FONT><FONT color=#444444>> Brillouin zone of cubic.
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<BR>
This could depend on the definition of "LO-TO splitting", which I meant "the reduction of the LO-TO degeneracy".
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If it is defined to be the splitting due to the long-range electric force on LO, it will disappear in BZ zone.
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Best Wishes!
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Yours Sincerely
<BR>
L. F. Huang
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------
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<BR>
L.F.Huang(黄良锋) DFT and phonon physics
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Add: Research Laboratory for Computational Materials Sciences,
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Instutue of Solid State Physics,the Chinese Academy of Sciences,
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P.O.Box 1129, Hefei 230031, P.R.China
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Tel: 86-551-5591464-326(office)
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Fax: 86-551-5591434
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Our group: <A href=http://theory.issp.ac.cn target=_blank>http://theory.issp.ac.cn</A>
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