[Pw_forum] about born effective charge tensors

[Paolo Giannozzi]

On Sunday 08 January 2006 08:01, sun jason wrote:

> I'm not sure about whether the born effective charge tensor
> should be symmetric in crystals.

in general they aren't. Note that the two indices refer to different 
things: the first to electric field polarization, the second to atomic
displacement.

Paolo

-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
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