MgO optimum mixing: Difference between revisions

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----
----
*{{TAG|INCAR}}
*{{TAG|INCAR}}
<pre>
##############################################
##############################################
## Optimum HSE mixing parameter ({{TAGBL|AEXX}}) for MgO
## Optimum HSE mixing parameter (AEXX) for MgO
## Expt gap = 7.8 eV
## Expt gap = 7.8 eV
## fit gap wrt. 0<{{TAGBL|AEXX}}<1
## fit gap wrt. 0<AEXX<1
## Compute the bandgap using different value of {{TAGBL|AEXX}}
## Compute the bandgap using different value of AEXX  
## in the range (0,1) and find the value which leads  
## in the range (0,1) and find the value which leads  
## to the best agreement with the experimental gap.  
## to the best agreement with the experimental gap.  
## hint: the gap grows lineraly with {{TAGBL|AEXX}}
## hint: the gap grows lineraly with AEXX
## Better preconverge with PBE first!
## Better preconverge with PBE first!
##############################################
##############################################
   
 
## Selects the HSE06 hybrid function
## Selects the HSE06 hybrid function
#{{TAGBL|LHFCALC}} = .TRUE. ; {{TAGBL|HFSCREEN}} = 0.2 ; {{TAGBL|AEXX}}=0.25   
#LHFCALC = .TRUE. ; HFSCREEN = 0.2 ; AEXX=0.25   
#{{TAGBL|ALGO}} = D ; {{TAGBL|TIME}} = 0.4  
#ALGO = D ; TIME = 0.4  
     
 
## Leave this in
## Leave this in
{{TAGBL|ISMEAR}} =  0
ISMEAR =  0
{{TAGBL|SIGMA}} =  0.01
SIGMA  =  0.01
{{TAGBL|GGA}}   = PE
GGA    = PE
 
</pre>


*{{TAG|KPOINTS}}
*{{TAG|KPOINTS}}
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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 ==

Revision as of 10:55, 15 March 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)

Download

5_2_MgO_mixing.tgz


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