MgO optimum mixing: Difference between revisions

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----
----
*INCAR
*{{TAG|INCAR}}
<pre>
<pre>
##############################################
##############################################
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</pre>
</pre>


*KPOINTS
*{{TAG|KPOINTS}}
<pre>
<pre>
k-points
k-points
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</pre>
</pre>


*POSCAR
*{{TAG|POSCAR}}
<pre>
<pre>
MgO
MgO
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The bandgap is obainted by substracting the eigenvalues written in cband.dat (conduction band  
The bandgap is obainted by substracting the eigenvalues written in cband.dat (conduction band  
minimum at Gamma) and vband.dat (valence band maximum at Gamma)
minimum at Gamma) and vband.dat (valence band maximum at Gamma)
== Used INCAR Tags ==
{{TAG|AEXX}}, {{TAG|ALGO}}, {{TAG|GGA}}, {{TAG|HFSCREEN}}, {{TAG|ISMEAR}}, {{TAG|LHFCALC}}, {{TAG|SIGMA}}


== Download ==
== Download ==
[http://www.vasp.at/vasp-workshop/examples/5_2_MgO_mixing.tgz 5_2_MgO_mixing.tgz]
[http://www.vasp.at/vasp-workshop/examples/5_2_MgO_mixing.tgz 5_2_MgO_mixing.tgz]
----
----
[[VASP_example_calculations|To the list of examples]] or to the [[The_VASP_Manual|main page]]
[[VASP_example_calculations|To the list of examples]] or to the [[The_VASP_Manual|main page]]


[[Category:Examples]]
[[Category:Examples]]

Revision as of 10:23, 17 February 2017

Description: find optimum HSE mixing parameter for MgO


##############################################
## Optimum HSE mixing parameter (AEXX) for MgO
## Expt gap = 7.8 eV
## fit gap wrt. 0<AEXX<1
## Compute the bandgap using different value of AEXX 
## in the range (0,1) and find the value which leads 
## to the best agreement with the experimental gap. 
## hint: the gap grows lineraly with AEXX
## Better preconverge with PBE first!
##############################################

## Selects the HSE06 hybrid function
#LHFCALC = .TRUE. ; HFSCREEN = 0.2 ; AEXX=0.25  
#ALGO = D ; TIME = 0.4 

## Leave this in
ISMEAR =  0
SIGMA  =  0.01
GGA    = PE

k-points
0
Gamma
  4  4  4
  0  0  0
MgO
-18.79350000000000000000
0.5 0.5 0.0
0.0 0.5 0.5
0.5 0.0 0.5
1 1
cart
0.00 0.00 0.00
0.50 0.0 0.0
  • script to extract G-eigenvalues and calculate the bandgap
grep "      4     " OUTCAR | head -8 | \
awk 'BEGIN{i=1}{a[i]=$2 ; i=2} END{for (j=1;j<i;j++) print j,a[j]}' > vband.dat
grep "      5     " OUTCAR | head -8 | \
awk 'BEGIN{i=1}{a[i]=$2 ; i=2} END{for (j=1;j<i;j++) print j,a[j]}' > cband.dat

The bandgap is obainted by substracting the eigenvalues written in cband.dat (conduction band minimum at Gamma) and vband.dat (valence band maximum at Gamma)

Used INCAR Tags

AEXX, ALGO, GGA, HFSCREEN, ISMEAR, LHFCALC, SIGMA

Download

5_2_MgO_mixing.tgz


To the list of examples or to the main page