MgO optimum mixing: Difference between revisions
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== Task == | |||
- | Find optimum HSE mixing parameter for MgO. | ||
== Input == | |||
=== {{TAG|POSCAR}} === | |||
<pre> | |||
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 | |||
</pre> | |||
=== {{TAG|INCAR}} ==== | |||
############################################## | ############################################## | ||
## Optimum HSE mixing parameter ({{TAGBL|AEXX}}) for MgO | ## Optimum HSE mixing parameter ({{TAGBL|AEXX}}) for MgO | ||
| Line 25: | Line 41: | ||
{{TAGBL|GGA}} = PE | {{TAGBL|GGA}} = PE | ||
=== {{TAG|KPOINTS}} === | |||
<pre> | <pre> | ||
k-points | k-points | ||
| Line 34: | Line 50: | ||
</pre> | </pre> | ||
== Calculation == | |||
*script to extract G-eigenvalues and calculate the bandgap | *script to extract G-eigenvalues and calculate the bandgap | ||
Revision as of 08:40, 19 May 2017
Overview > bandgap of Si using different DFT+HF methods > MgO optimum mixing > fcc Ni DOS with hybrid functional > Si bandstructure > List of tutorials
Task
Find optimum HSE mixing parameter for MgO.
Input
POSCAR
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
INCAR =
############################################## ## 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
KPOINTS
k-points 0 Gamma 4 4 4 0 0 0
Calculation
- 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
To the list of examples or to the main page