Improving the dielectric function

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Revision as of 12:04, 17 September 2019 by Cesare (talk | contribs) (→‎Calculation)

Task

Calculate the dielectric function of Si using an averaging over multiple grids or a model-BSE to improve k-sampling in BSE calculations.

Input

Si
 5.4300
0.5 0.5 0.0
0.0 0.5 0.5
0.5 0.0 0.5
2
cart
0.00 0.00 0.00 
0.25 0.25 0.25 

INCAR

  • This is the INCAR file for the basic DFT calculation:
System  = Si
PREC = Normal ; ENCUT = 250.0
ISMEAR = 0 ; SIGMA = 0.01
KPAR = 2
EDIFF = 1.E-8

KPOINTS

Automatic
 0
Gamma
 4 4 4 
 0 0 0

Calculation

The calculated spectra can be improved in two ways:

  • Averaging over multiple grids:
Compute N independent dielectric functions using BSE (or any other method), using shifted grids of k-points, and take the average over the results.
  • Model-BSE:
Use a parametrized model[1] Cite error: Closing </ref> missing for <ref> tag

[2] </references>


Back to the main page

  1. Cite error: Invalid <ref> tag; no text was provided for refs named bokdam:scr:6
  2. P.Liu et al., Phys. Rev. Materials 2, 075003 (2018).