[Pw_forum] How to calculate the polarization value

[Q.J.Wang]

Dear all,
 I want to calculate the polarization value of BiFeO3 via the Berry phase,but I don't know how to do it.  The example 10  shows how to calculate the polarization via Berry phase  in PbTiO3, however, in the example, the PbTiO3 is paraelectric pahse before removing the Pb ion to 0.01 position, so I don't know how to calculate the polarization of ferroelectric phase BiFeO3. Is it necessary to find the paraelectric phase of BiFeO3 and later removing the Bi ion like example 10?  Can I calculate the polarization directly of the ferroelectric phase BiFeO3 not removing the Bi ion? Thank you very much for any help.







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Best regards
 
Q.J.Wang
 
XiangTan University
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