MgO optimum mixing: Difference between revisions
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*{{TAG|INCAR}} | *{{TAG|INCAR}} | ||
############################################## | |||
############################################## | ## 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 | |||
*{{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) | ||
== 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
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