GW doubts
Posted: Tue Oct 11, 2011 7:03 am
Dear Developers, dear All,
I am trying fixing point-by-point some doubts I am not completely able to understand about GW in VASP. I usually followed the procedure suggested by the manual, but I would like to be more sure about the physiscs implemented in VASP.
1. GW in VASP uses Plasmon Pole approximation or Omega integration. From the paper (Shishkin Kresse, PRB 2006) it seems a Plasmon Pole, but I am not able to deeply understand if so.
2. How does VASP calculate the dielectric constant? RPA or some model epsilon?
3. How to include local fields in the calculation?
LGWLF = T and
ENCUTLF = ... cutoff for local field effects
is suffuicient?
4. Have someone experience with the "DIM" flag. I am calculating optical properties of a sheet so I wonder if DIM=2 (it should) is the correct tag to be activated
Thanks in advance!
Best,
Giac
I am trying fixing point-by-point some doubts I am not completely able to understand about GW in VASP. I usually followed the procedure suggested by the manual, but I would like to be more sure about the physiscs implemented in VASP.
1. GW in VASP uses Plasmon Pole approximation or Omega integration. From the paper (Shishkin Kresse, PRB 2006) it seems a Plasmon Pole, but I am not able to deeply understand if so.
2. How does VASP calculate the dielectric constant? RPA or some model epsilon?
3. How to include local fields in the calculation?
LGWLF = T and
ENCUTLF = ... cutoff for local field effects
is suffuicient?
4. Have someone experience with the "DIM" flag. I am calculating optical properties of a sheet so I wonder if DIM=2 (it should) is the correct tag to be activated
Thanks in advance!
Best,
Giac