ABINIT Discussion Forums

Hello,
i am calculating polarization of tetragonal phase of bifeo3.since i wana to calculate it in direction of (0 0 1) i choosed rfdir 0 0 1 and i fited berryopt -1 but there isn't polarization in cartesian coordinate in my out file.
could you please tell me why i haven't polarization in cartesian coordinate?
Thankyou.Best regards.
input:
acell 3.72 3.72 4.67 angstrom
angdeg 90 90 90
natom 5
ntypat 3
znucl 83 26 8
typat 1 2 3 3 3
ecut 35
ngkpt 2 2 2
kptopt 4
xred 0.000 0.000 0.000
0.500 0.500 0.410
0.500 0.500 -0.101
0.500 0.000 0.367
0.000 0.500 0.367
berryopt -1
rfdir 0 0 1
toldfe 1.0d-12
ixc 1
iscf 7
nstep 50
nbdbuf 0
i have just this part in my out file:
Computing the polarization (Berry phase) for reciprocal vector:
0.00000 0.00000 0.50000 (in reduced coordinates)
0.00000 0.00000 0.05666 (in cartesian coordinates - atomic units)
Number of strings: 4
Number of k points in string: 2

Summary of the results
Electronic Berry phase -4.805979700E-01
Ionic phase -9.220000000E-01
Total phase -1.402597970E+00
Remapping in [-1,1] 5.974020300E-01

Polarization 1.208879677E-02 (a.u. of charge)/bohr^2
Polarization 6.916576236E-01 C/m^2

Always use rfdir 1 1 1 with berryopt -1 or berryopt 4. It will calculate polarization in all three cartesian directions. The computational overhead of doing this is negligible. Look in the output file for the Total: line, it will give the polarizations in each direction. Just use the one you want.