Strange huge dipole moment value
Posted: Tue Jul 15, 2014 10:42 am
Hello
I computed IR frequencies at gamma point by finite differences for a molecule in a 15 x 15 x 15 (A) cell. Here is the INCAR :
PREC = Accurate
EDIFF = 1e-6
ENCUT = 500.0
IDIPOL = 4
NSW = 1
IBRION = 5
POTIM = 0.015
NFREE = 2
ISMEAR = 0
SIGMA = 0.05
Looking at dipole moment values for each displacement, I obtain in several cases an huge value of the dipole moment. For example, 71 instead of 2. I tried smaller values of POTIM but it did not fix this issue. The large values of the dipole moment seems not to be correlated to the energy of the structures and they do not involve a specific atom.
Have you got an advice to look at the origin of this strange values ?
I computed IR frequencies at gamma point by finite differences for a molecule in a 15 x 15 x 15 (A) cell. Here is the INCAR :
PREC = Accurate
EDIFF = 1e-6
ENCUT = 500.0
IDIPOL = 4
NSW = 1
IBRION = 5
POTIM = 0.015
NFREE = 2
ISMEAR = 0
SIGMA = 0.05
Looking at dipole moment values for each displacement, I obtain in several cases an huge value of the dipole moment. For example, 71 instead of 2. I tried smaller values of POTIM but it did not fix this issue. The large values of the dipole moment seems not to be correlated to the energy of the structures and they do not involve a specific atom.
Have you got an advice to look at the origin of this strange values ?