Dipol corrections seem too big
Posted: Thu Feb 17, 2011 7:40 pm
I am performing some calculations on a slab of an ionic material with an organic molecule above it. I have IDPOL set to IDIPOL=3, and for certain calculations the corrections seem to be working properly (in any case, the corrections seem to be of a reasonable size).
The issue I am having is that the dipole corrections in the z-direction seem to be much too large for certain other calculations -- on the order of a few eV, and I am wondering what the reason is. When I check
grep 'min pos' OUTCAR
to find the plane which is used to make the dipole calculation, it seems to be at a reasonable position in the cell, i.e. at the charge minimum. Is it likely to help if I use a finer FFT mesh (the cell is rather long in the z-direction)? Is there anything else I should try in order to get the dipole corrections to be calculated properly?
The issue I am having is that the dipole corrections in the z-direction seem to be much too large for certain other calculations -- on the order of a few eV, and I am wondering what the reason is. When I check
grep 'min pos' OUTCAR
to find the plane which is used to make the dipole calculation, it seems to be at a reasonable position in the cell, i.e. at the charge minimum. Is it likely to help if I use a finer FFT mesh (the cell is rather long in the z-direction)? Is there anything else I should try in order to get the dipole corrections to be calculated properly?