The ABINIT Users Mailing List ( CLOSED )

[Chol-Jun Yu <yucj@ghi.rwth-aachen.de>]

Dear ABINITers,

thank you very much for your advices. As Yukihiro said, I performed  
Berry-phase calculation for the centrosymetric state (state without the 
atomic relaxations). Here, concerning the PbTiO3, the polarization of 
centrosymetric state was 0.0 and one of the ferroelectric state was -0,889. 
Concerning the BiScO3, the valuse were -0.624 and 0.185, repectively.

So I conclude that the spontaneous polarization of PT is 0.889c/m2 and one of 
BS is 0.809c/m2. Is it right?

With best regards,

Yu Chol-Jun
-----------------------------------------------------------------------------
Computational Materials Engineering(CME)
Center for Computational Engineering Science(CCES)
Institute of Mineral Engineering(GHI), RWTH Aachen
Mauerstrasse 5, D-52064 Aachen, Germany
Tel: ++49 241 80 94969
Fax: ++49 241 80 92271
e-mail: yucj@ghi.rwth-aachen.de
-----------------------------------------------------------------------------
PbTiO3
in centrosymetric state
Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic:  0.126849541E-11   0.178732484E-11  -0.223809051E-11
     Ionic:       0.000000000E+00   0.000000000E+00   0.000000000E+00
     Total:       0.126849541E-11   0.178732484E-11  -0.223809051E-11

in ferroelectric state
Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic: -0.821058924E-12   0.148630108E-11   0.688563212E+00
     Ionic:       0.000000000E+00   0.000000000E+00   0.527575240E+00
     Total:      -0.821058924E-12   0.148630108E-11  -0.889090546E+00
     
BiScO3
in centrosymetric state
Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic: -0.716175102E-02  -0.716175103E-02  -0.693328481E-01
     Ionic:      -0.429705051E+00  -0.429705051E+00  -0.554662785E+00
     Total:      -0.436866802E+00  -0.436866802E+00  -0.623995633E+00

in ferroelectirc state
Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic: -0.980996878E-13  -0.114890272E-12  -0.148241867E+00
     Ionic:      -0.429705051E+00  -0.429705051E+00   0.332907991E+00
     Total:      -0.429705051E+00  -0.429705051E+00   0.184666123E+00