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<div>Dear Wang, H.:
<BR>
LO-TO splitting always exists in Brillouin zone, but two points are worth noting:
<BR>
(1) it is caused by short-range interactions, which are calculated directly from DFPT. The splitting at Gamma point is due to long-range dipolar interaction, which needs postprocessing with Born charge;
<BR>
(2) only cubic crystals has LO and TO braches.
<BR>
<BR>
Best Wishes!
<BR>
Yours Sincerely
<BR>
L. F. Huang
<BR>
<BR>
</FONT><FONT color=#444444>> From: xirainbow
<BR>
</FONT><FONT color=#444444>> Subject: Re: [Pw_forum] LO-TO splitting in dynmat.x
<BR>
</FONT><FONT color=#444444>> To: PWSCF Forum
<BR>
</FONT><FONT color=#444444>> Message-ID:
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</FONT><FONT color=#444444>> Content-Type: text/plain; charset="iso-8859-1"
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> Dear all:
<BR>
</FONT><FONT color=#444444>> Is there LO-TO splitting far away from Gamma point?
<BR>
</FONT><FONT color=#444444>> How large is the influence range of LO-TO splitting in Brillouin zone? One
<BR>
</FONT><FONT color=#444444>> hundred percent?
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</FONT><FONT color=#444444>> Thanks in advance;)
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</FONT><FONT color=#444444>>
<BR>
</FONT><FONT color=#444444>> --
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</FONT><FONT color=#444444>> ____________________________________
<BR>
</FONT><FONT color=#444444>> Hui Wang
<BR>
</FONT><FONT color=#444444>> School of physics, Fudan University, Shanghai, China
<BR>
<BR>
<BR>
<BR>
------
<BR>
======================================================================
<BR>
L.F.Huang(黄良锋) DFT and phonon physics
<BR>
======================================================================
<BR>
Add: Research Laboratory for Computational Materials Sciences,
<BR>
Instutue of Solid State Physics,the Chinese Academy of Sciences,
<BR>
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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======================================================================
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