Dear Experts,
I am calculating the band gap of a 6-atom heterostructure using the GW0 method in VASP. I am currently checking the convergence of the calculated band gap with respect to the k-point sampling.
However, I find that the GW0 band gap changes significantly when I change the k-point mesh. The band gaps I obtained are:
k-point mesh GW_0 band gap (eV)
6*6*1 2.2066
7*7*1 2.4651
9*9*1 2.1481
11*11*1 2.0854
15*15*1 2.0610
17*17*1 1.79
21*21*1 2.0006
As can be seen, the band gap does not show a clear convergence trend with increasing k-point density. The system contains only 6 atoms, but the GW0 calculations are computationally expensive. With my available computational resources, a 21*21*1 mesh is approximately the maximum k-point density that I can practically use.
I would therefore like to ask whether there may be something in my calculation setup that I should check or modify.
I have attached my POSCAR and INCAR files. I need suggestions to obtain a reliable GW0 band gap.
https://drive.google.com/drive/folders/ ... drive_link
