Bandgap of Si using different DFT+HF methods: Difference between revisions
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*INCAR | *{{TAG|INCAR}} | ||
<pre> | <pre> | ||
## Better preconverge with PBE first | ## Better preconverge with PBE first | ||
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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> | ||
System: Si | System: Si | ||
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</pre> | </pre> | ||
== Used INCAR Tags == | |||
{{TAG|AEXX}}, {{TAG|AGGAC}}, {{TAG|AGGAX}}, {{TAG|ALDAC}}, {{TAG|ALGO}}, {{TAG|GGA}}, {{TAG|HFSCREEN}}, {{TAG|ISMEAR}}, {{TAG|LHFCALC}}, {{TAG|SIGMA}} | |||
== Download == | == Download == | ||
[http://www.vasp.at/vasp-workshop/examples/Si_hybrids_gap.tgz Si_hybrids_gap.tgz] | [http://www.vasp.at/vasp-workshop/examples/Si_hybrids_gap.tgz Si_hybrids_gap.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 10:19, 17 February 2017
Description: Bandgap of Si using different DFT+HF schemes (PBE, B3LYP, PBE0, HSE06, and HF)
## Better preconverge with PBE first ## and use the WAVECAR file as inout for the DFT+HF calculation ## Selects the B3LYP hybrid function #LHFCALC = .TRUE. ; GGA = B3 ; AEXX = 0.2 ; AGGAX = 0.72 #AGGAC = 0.81 ; ALDAC = 0.19 #ALGO = D ; TIME = 0.4 ## Selects the PBE0 hybrid function #LHFCALC = .TRUE. ; #ALGO = D ; TIME = 0.4 ## Selects the HSE06 hybrid function #LHFCALC = .TRUE. ; HFSCREEN = 0.2 ; #ALGO = D ; TIME = 0.4 ## Selects HF #LHFCALC = .TRUE. ; AEXX = 1.0 ; ALDAC = 0.0 ; AGGAC = 0 #ALGO = D ; TIME = 0.4 ## Leave this in ISMEAR = 0 SIGMA = 0.01 GGA = PE
k-points 0 Gamma 6 6 6 0 0 0
System: Si 5.430 0.5 0.5 0.0 0.0 0.5 0.5 0.5 0.0 0.5 1 Cartesian 0 0 0 0.25 0.25 0.25
- script to extract eigenvalues and calculate the bandgap
homo=`awk '/NELECT/ {print $3/2}' $1`
lumo=`awk '/NELECT/ {print $3/2+1}' $1`
nkpt=`awk '/NKPTS/ {print $4}' $1`
e1=`grep " $homo " $1 | head -$nkpt | sort -n -k 2 | tail -1 | awk '{print $2}'`
e2=`grep " $lumo " $1 | head -$nkpt | sort -n -k 2 | head -1 | awk '{print $2}'`
echo "HOMO: band:" $homo " E=" $e1
echo "LUMO: band:" $lumo " E=" $e2
- type
./gap.sh OUTCAR
- README.txt
For each HF+DFT method (B3LYP, PBE0, HSE06, and HF) compute the bandgap of Si
adopting the following procedure:
i) Perform a standard PBE calculation
ii) Perform a HF+DFT run (VASP reads in the WAVECAR from run (i)
iii) Calculate the value of the bandgap by running the script 'gap':
bandgap = min(cband) - max(vband)
Used INCAR Tags
AEXX, AGGAC, AGGAX, ALDAC, ALGO, GGA, HFSCREEN, ISMEAR, LHFCALC, SIGMA
Download
To the list of examples or to the main page