Dielectric properties of Si

Overview > dielectric properties of SiC > dielectric properties of Si  > Ionic contributions to the frequency dependent dielectric function of NaCl  > List of tutorials

Description: the static and frequency dependent dielectric properties of Si.

---

Please have a look at the example on calculation of the static and frequency dependent dielectric properties of SiC first. The same procedures apply to this example.

• INCAR file for the static calculation

## Static dielectric properties by means of DFPT
#NBANDS = 4
#EDIFF = 1E-6
#LEPSILON = .TRUE.
## try to add this to the DFPT calculation
#LPEAD = .TRUE.
## to get the ionic contributions to the
## static dielectric properties from
## perturbation theory
#IBRION = 8
        
## Static dielectric properties by means of PEAD
#EDIFF = 1E-8      # finite field requires very tight convergence
#LCALCEPS = .TRUE.
#NELM = 100
        
## Leave this in
ISMEAR = 0
SIGMA = 0.01
GGA = PE

• INCAR for the frequency dependent calculation

## Frequency dependent dielectric tensor without
## local field effects
#ALGO = Exact
#NBANDS  = 64
#LOPTICS = .TRUE. ; CSHIFT = 0.1
#NEDOS = 2000
## and you might try with the following
#LPEAD = .TRUE.
    
## Frequency dependent dielectric tensor with and
## without local field effects in RPA and due to
## changes in the DFT xc-potential
## N.B.: beware one first has to have done a
## calculation with LOPTICS = .TRUE. (see above)
#ALGO = CHI ; LSPECTRAL = .FALSE.
#LRPA = .FALSE.
## be sure to take the same number of bands as for
## the LOPTICS = .TRUE. calculation, otherwise the
## WAVEDER file is not read correctly
# NBANDS = 64
    
## Leave this in
ISMEAR = 0
SIGMA = 0.01
GGA = PE

• POSCAR

system Si
5.430
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

Used INCAR Tags

ALGO, CSHIFT, EDIFF, GGA, IBRION, ISMEAR, LCALCEPS, LEPSILON, LOPTICS, LPEAD, LRPA, NBANDS, NEDOS, NELM, SIGMA

Download

Si_dielectric.tgz

---

To the list of examples or to the main page