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Frequency Dependent Dielectric Tensor

PostPosted: Wed Dec 13, 2017 7:14 pm
by dscullion12
Dear VASP users,

Is there a way to calculate the frequency dependent dielectric tensor in VASP with ionic contributions. Figure 2 in a recent paper:

https://www.nature.com/articles/srep286 ... -chemistry

claims to have to done so using DFPT but I am unsure as to what combination of tags to use. Any help would be greatly appreciated.

Kind regards,

Declan

Re: Frequency Dependent Dielectric Tensor

PostPosted: Thu Dec 14, 2017 2:50 pm
by admin
This is a new feature, starting in version 5.4.3, but not documented
(the documentation will appear soon).
You need to merge electronic and ionic dielectric function.
The ionic dielectric function can be calculated in two ways:
1. DFPT (faster). IBRION=8; LEPSILON=.TRUE.
calculated dielectric function is in vasprun.xml
2. Finite differences (slower). IBRION=6; LPEAD=.TRUE; LCALCEPS=.TRUE.