Difficulty Reproducing Dielectric Constants for GaAs in AMSET Example

Hi,
I have recently started working with AMSET, and as a first step, I am attempting to reproduce the GaAs example provided on the GitHub repository (amset/examples at main · hackingmaterials/amset · GitHub).

This is my INCAR:
ISTART =1
PREC = Accurate
ENCUT = 520
ISMEAR = 0
SIGMA = 0.001
ISPIN = 1
ICHARG = 2
ALGO = Normal
EDIFF = 1E-8
LREAL = .FALSE.
NBANDS = 39
NEDOS = 601
ISIF = 2
ISYM = 0
LORBIT = 11
NSW = 1
IBRION = 8
LWAVE = F
LCHARG = F
LVHAR = T
LAECHG = F
NELM = 100
ADDGRID = True
LEPSILON = True

According to the example, the reported values are:

  • High-frequency dielectric: 10.32

  • Static dielectric: 12.18

  • POP frequency: 8.16 THz

However, I am unable to reproduce these values. From my calculation, I obtain:

Macroscopic Static Dielectric Tensor – Ionic Contribution:

Copy code

  2.220571  0.000752  0.000489  
  0.000752  2.220571  0.000489  
  0.000489  0.000489  2.220882  

Macroscopic Static Dielectric Tensor (including local field effects in DFT):

Macroscopic Static Dielectric Tensor (including local field effects in DFT):
27.257691 0.000015 -0.000028
0.000049 27.257690 -0.000062
0.000065 0.000099 27.257688



I noticed that the example uses a **17×17×17** k-point mesh, whereas I used **31×31×31**, which makes me wonder if I may be incorrectly setting something else. Do you think I should continue optimizing the k-point grid, or could the discrepancy be due to another parameter?

Any guidance would be greatly appreciated.

Thank you.