- Date: 2020/11/26 02:11
- Name: Naoya Yamaguchi
>1) How much each ion displacement should be considered ?
I think it is better to find a linear part in the relation between polarization and displacements with several trials.
>2) Should displacement be applied to all ions of that type? for example, we have four ions of that type.
You need to shift only the position of ions whose Born effective charges you want to calculate. You should also consider which direction displacements is along.
>3) Is necessary optimization of lattice constants and geometry optimization (relaxation of structure) ?
As the electronic structures change, I think that it depends on cases, and you can use some experimental lattice constants, for example.