How to fix this problem about Berry phase calculation ?
Posted: Sat Aug 04, 2007 7:26 pm
After relax and get charge, we set;
LBERRY = .TRUE.
IGPAR = 1
NPPSTR = 3
DIPOL = 0.50 0.50 0.60
we get;
<R>ion = 0.00000 -220.10268 142.06428
but for IGPAR = 2 and 3, we get;
<R>ion = 0.00000 0.00000 345.89482
I calculate from undistorted system. It seem to have some error from my calculation. Why do we get a large change of <R>ion ?
------------------------------------------------
Automatic mesh
0 ! number of k-points = 0 ->automatic generation scheme
Monkhrost ! generate a Gamma centered grid
4 4 4 !
0.5 0.5 0.5
-------------------------------------------------
LBERRY = .TRUE.
IGPAR = 1
NPPSTR = 3
DIPOL = 0.50 0.50 0.60
we get;
<R>ion = 0.00000 -220.10268 142.06428
but for IGPAR = 2 and 3, we get;
<R>ion = 0.00000 0.00000 345.89482
I calculate from undistorted system. It seem to have some error from my calculation. Why do we get a large change of <R>ion ?
------------------------------------------------
Automatic mesh
0 ! number of k-points = 0 ->automatic generation scheme
Monkhrost ! generate a Gamma centered grid
4 4 4 !
0.5 0.5 0.5
-------------------------------------------------