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[sathya <sathya_sheela1985001@rediffmail.com>]

Dear All,
             I am trying to find the born effective charge for cubic YMnO3 but
am getting very high values from the output.I am moving 1% of the acell in 
Bohr
and calculating from the change in polarization for movement for the positive
and negative displacements fo Y Mn and O.I am attaching the input and part of
the O/P file. Any suggestions are welcome  

# Finite difference calculation of the Born effective charges of cubic ymno3
# (M. Veithen, 29.4.2005)
#

#Definition of the different datasets 
#************************************
 
ndtset 7
jdtset 1 2 3 4 5 6 7

     xcart1   0.0000000000E+00  0.0000000000E+00  0.0000000000E+00
              3.6849500000E+00  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  3.6849500000E+00  0.0000000000E+00
              4.5126131835E-16  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  2.2563065918E-16  3.6849500000E+00

     xcart2   0.0736990000E+00  0.0000000000E+00  0.0000000000E+00
              3.6849500000E+00  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  3.6849500000E+00  0.0000000000E+00
              4.5126131835E-16  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  2.2563065918E-16  3.6849500000E+00


     xcart3   -.0736990000E+00  0.0000000000E+00  0.0000000000E+00
              3.6849500000E+00  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  3.6849500000E+00  0.0000000000E+00
              4.5126131835E-16  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  2.2563065918E-16  3.6849500000E+00

     xcart4   0.0000000000E+00  0.0000000000E+00  0.0000000000E+00
              3.75864900000E+00  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  3.6849500000E+00  0.0000000000E+00
              4.5126131835E-16  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  2.2563065918E-16  3.6849500000E+00

     xcart5   0.0000000000E+00  0.0000000000E+00  0.0000000000E+00
              3.6112510000E+00  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  3.6849500000E+00  0.0000000000E+00
              4.5126131835E-16  3.6849500000E+00  3.6849500000E+00
              3.6849500000E+00  2.2563065918E-16  3.6849500000E+00

     xcart6   0.0000000000E+00  0.0000000000E+00  0.0000000000E+00
              3.6849500000E+00  3.6849500000E+00  3.6849500000E+00
              3.7586490000E+00  3.6849500000E+00  0.0000000000E+00
              0.01000000000000  3.6849500000E+00  3.6849500000E+00
              3.7586490000E+00  2.2563065918E-16  3.6849500000E+00

     xcart7   0.0000000000E+00  0.0000000000E+00  0.0000000000E+00
              3.6849500000E+00  3.6849500000E+00  3.6849500000E+00
              3.6112510000E+00  3.6849500000E+00  0.0000000000E+00
              -.01000000000000  3.6849500000E+00  3.6849500000E+00
              3.6112510000E+00  2.2563065918E-16  3.6849500000E+00


#Definition of the elementary cell
#*********************************
   acell  7.3699  7.3699  7.3699
angdeg 90 90 90  
#Definition of the atoms
#***********************
   natom 5
   ntypat 3
   znucl 39  25  8
  # spgroup  221
   typat 1 2 3 3 3
   ixc 1

#Definition of the SCF procedure
#*******************************
   iscf 5
   nstep 1000


#Definition of the plane wave basis set
#**************************************
   ecut  40
   ecutsm 0.5
   dilatmx 1.05
   kptopt 1
   ngkpt 6 6 6
   shiftk  0 0 0
    toldfe 1.0d-4

# Berry phase calculation of the polarization
#********************************************
   berryopt -1
   rfdir 1 1 1


for Y movement in xred=.01 or xcart=.073699 movement is in x axis

 Polarization in cartesian coordinates (a.u.):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.648502226E-03   0.519926305E-02  
0.418131244E-02  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.865315868E-02  -0.920548796E-02 
-0.920548796E-02  
     Total:                        -0.930166091E-02  -0.400622491E-02 
-0.502417551E-02

 Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.371039002E-01   0.297474595E+00  
0.239232794E+00  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.495088410E+00  -0.526689798E+00 
-0.526689798E+00  
     Total:                        -0.532192310E+00  -0.229215203E+00 
-0.287457004E+00

for Y movement in xred=-.01 or xcart=-.073699 movement is in x axis

Polarization in cartesian coordinates (a.u.):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.599410096E-02   0.655736562E-02  
0.755351557E-02  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.975781723E-02  -0.920548796E-02 
-0.920548796E-02  
     Total:                        -0.157519182E-01  -0.264812233E-02 
-0.165197238E-02

 Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.342951057E+00   0.375178110E+00  
0.432172592E+00  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.558291186E+00  -0.526689798E+00 
-0.526689798E+00  
     Total:                        -0.901242243E+00  -0.151511688E+00 
-0.945172059E-01


for Mn movement in xred=0.01 or xcart=0.073699 movement is in x axis

 Polarization in cartesian coordinates (a.u.):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.139476229E-02   0.937705312E-03 
-0.206983548E-02  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.791671964E-02  -0.920548796E-02 
-0.920548796E-02  
     Total:                        -0.931148193E-02  -0.826778265E-02 
-0.112753234E-01

 Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.798009917E-01   0.536505857E-01 
-0.118425143E+00  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.452953226E+00  -0.526689798E+00 
-0.526689798E+00  
     Total:                        -0.532754218E+00  -0.473039212E+00 
-0.645114941E+00


for Mn movement in xred=-.01 or xcart=-.073699 movement is in x axis

 Polarization in cartesian coordinates (a.u.):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:        0.693042190E-02   0.284576891E-02  
0.281335699E-02  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.104942563E-01  -0.920548796E-02 
-0.920548796E-02  
     Total:                        -0.356383437E-02  -0.635971905E-02 
-0.639213097E-02

 Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:        0.396522436E+00   0.162819989E+00  
0.160965549E+00  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.600426369E+00  -0.526689798E+00 
-0.526689798E+00  
     Total:                        -0.203903933E+00  -0.363869808E+00 
-0.365724249E+00



for O movement in xred=+.01 or xcart=+.073699 movement is in x axis

 Polarization in cartesian coordinates (a.u.):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.312615041E-02   0.633696057E-02  
0.642407623E-02  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.684628299E-02  -0.920548796E-02 
-0.920548796E-02  
     Total:                        -0.997243339E-02  -0.286852738E-02 
-0.278141173E-02

 Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:       -0.178861950E+00   0.362567688E+00  
0.367551989E+00  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.391708448E+00  -0.526689798E+00 
-0.526689798E+00  
     Total:                        -0.570570398E+00  -0.164122110E+00 
-0.159137809E+00


for O movement in xred=-.01 or xcart=-.073699 movement is in x axis

 Polarization in cartesian coordinates (a.u.):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:        0.506685030E-02   0.123537138E-03 
-0.389953469E-02  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.115646929E-01  -0.920548796E-02 
-0.920548796E-02  
     Total:                        -0.649784263E-02  -0.908195082E-02 
-0.131050226E-01

 Polarization in cartesian coordinates (C/m^2):
 (the sum of the electronic and ionic Berry phase has been fold into [-1, 1])
     Electronic berry phase:        0.289898631E+00   0.706814788E-02 
-0.223110947E+00  
     Expectation value (PAW only):  0.000000000E+00   0.000000000E+00  
0.000000000E+00  
     Ionic:                        -0.661671147E+00  -0.526689798E+00 
-0.526689798E+00  
     Total:                        -0.371772516E+00  -0.519621650E+00 
-0.749800745E+00


Thank you in advance for any suggestions  and sorry for the long file.

Regards
Sathya Sheela.S
Grad student
National Institute of Technology
Trichy ,India