How to do the Total DOS calculation

We need the 4 input files for a SCF calculation and modified INCAR KPOINT files for dos calculation

POSCAR

fcc Si:
 3.9
 0.5 0.5 0.0
 0.0 0.5 0.5
 0.5 0.0 0.5
   1
cartesian
0 0 0

     Fcc Si lattice constant of 3.9  .
    1 atom per unit cell.

 

INCAR

System = fcc Si
ISTART = 0 ; ICHARG = 2
ENCUT = 240
ISMEAR = 0; SIGMA = 0.1

    Initial charge density form overlapping atoms.
    Energy cutoff of 240 eV from POTCAR file.
 

KPOINTS

k-points
 0
Monkhorst Pack
 11 11 11
 0  0  0

 

POTCAR

Download the pseudopotential file from this link POTCAR

NB: you can download the input files from fccSi.tgz

 

SCF calculation

First we need to do a scf calculation to get the  CHGCAR file

/Si_dos> vasp_std

 

DOS calculation

• Perform a static (NSW=0, IBRION=-1) self consistent calculation for the DOS (the DOS is found in the DOSCAR file.

• For large systems:
  • Converge with a small number of k points.
  • Increase the number of k points for the DOS and set ICHARG=11 (charge density from the last self-consistent run). ICHARG=11 treats each k point independently and keeps the charge density and the potential fixed.

Read CHGCAR from previous run.

The smearing of the k points is set to the tetrahedron method with Blöchl corrections (ISMEAR=-5 to fi the problem

INCAR

System = fcc Si 
# ICHARG = 11 #charge read file
ENCUT  =    240
ISMEAR = -5 #tetrahedron
LORBIT = 11

    Initial charge density form overlapping atoms.
    Energy cutoff of 240 eV from POTCAR file.
 

KPOINTS

k-points
 0
Monkhorst Pack
 21 21 21
 0  0  0

Kpoint from 11x11x11 to 21x21x21

/Si_dos> vasp_std

 

Plotting DOS

To plot the total DOS we use the following script plotdos.sh

awk 'BEGIN{i=1} /total>/,\
                /\/total>/ \
                 {a[i]=$2 ; b[i]=$3 ; i=i+1} \
     END{for (j=10;j<i-4;j++) print a[j],b[j]}' vasprun.xml > dos.dat

ef=`awk '/efermi/ {print $3}' vasprun.xml`

cat >plotfile<<!
# set term postscript enhanced eps colour lw 2 "Helvetica" 20
# set output "optics.eps"
plot "dos.dat" using (\$1-$ef):(\$2) w lp
!

gnuplot -persist plotfile

# rm dos.dat plotfile

/Si_dos> chmod +x plotdos.sh

/Si_dos> ./plotdos.sh

 

or using p4vasp tool

/Si_dos> p4v [vasprun.xml]

 

Download

fccSidos.tgz

 

Reference:https://www.vasp.at/wiki/index.php/Fcc_Si_DOS