[Pw_forum] LO-TO splitting in dynmat.x

[Eyvaz Isaev]

From: xirainbow <nkxirainbow at gmail.com>


> Is there LO-TO splitting far away from Gamma point?

No.


>How large is the influence range of LO-TO splitting in Brillouin zone? One 
>hundred percent?

It depends on the macroscopic dielectric constant and  Born effective charge, 
see  any good solid state physics textbook 

or review paper Rev.Mod.Phys. 73, 515 (2001). 
It is clear that the effect is more pronounced for (polar) insulators (large 
band gap). 



Bests,
Eyvaz.


  -------------------------------------------------------------------
Prof. Eyvaz Isaev, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
Sweden 

Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
Russia, 

isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
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