How to set DIPOL?
Posted: Sat Nov 12, 2011 3:28 pm
Dear all. I am a beginer of VASP. I want to calculate polarization by berry-phase method. As the manual says, dipol is the center of the cell, so is the way to calculate the center shown below correct ?
r_{+} = \Sum_{i} Z_{i} *r_{i} /\Sum_{i} Z_{i}
for (plus charge ion : i run for plus ion)
and
r_{-} = \Sum_{i} Z_{i} *r_{i} /\Sum_{i} Z_{i}
for (minus charge ion : i run for minus ions r_{i} is minus ion position)
and the center of dipole r_{0} is just the center of plus ion cnter r_{+}
and minus ion center r_{-},
r_{0} = 0.5 * (r_{+} + r_{-})
r_{+} = \Sum_{i} Z_{i} *r_{i} /\Sum_{i} Z_{i}
for (plus charge ion : i run for plus ion)
and
r_{-} = \Sum_{i} Z_{i} *r_{i} /\Sum_{i} Z_{i}
for (minus charge ion : i run for minus ions r_{i} is minus ion position)
and the center of dipole r_{0} is just the center of plus ion cnter r_{+}
and minus ion center r_{-},
r_{0} = 0.5 * (r_{+} + r_{-})