Bandgap of Si using different DFT+HF methods: Difference between revisions
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## Selects the B3LYP hybrid function | ## Selects the B3LYP hybrid function | ||
#LHFCALC = .TRUE. ; GGA = B3 ; AEXX = 0.2 ; AGGAX = 0.72 | #{{TAGBL|LHFCALC}} = .TRUE. ; {{TAGBL|GGA}} = B3 ; {{TAGBL|AEXX}} = 0.2 ; {{TAGBL|AGGAX}} = 0.72 | ||
#AGGAC = 0.81 ; ALDAC = 0.19 | #{{TAGBL|AGGAC}} = 0.81 ; {{TAGBL|ALDAC}} = 0.19 | ||
#ALGO = D ; TIME = 0.4 | #{{TAGBL|ALGO}} = D ; {{TAGBL|TIME}} = 0.4 | ||
## Selects the PBE0 hybrid function | ## Selects the PBE0 hybrid function | ||
#LHFCALC = .TRUE. ; | #{{TAGBL|LHFCALC}} = .TRUE. ; | ||
#ALGO = D ; TIME = 0.4 | #{{TAGBL|ALGO}} = D ; {{TAGBL|TIME}} = 0.4 | ||
## Selects the HSE06 hybrid function | ## Selects the HSE06 hybrid function | ||
#LHFCALC = .TRUE. ; HFSCREEN = 0.2 ; | #{{TAGBL|LHFCALC}} = .TRUE. ; {{TAGBL|HFSCREEN}} = 0.2 ; | ||
#ALGO = D ; TIME = 0.4 | #{{TAGBL|ALGO}} = D ; {{TAGBL|TIME}} = 0.4 | ||
## Selects HF | ## Selects HF | ||
#LHFCALC = .TRUE. ; AEXX = 1.0 ; ALDAC = 0.0 ; AGGAC = 0 | #{{TAGBL|LHFCALC}} = .TRUE. ; {{TAGBL|AEXX}} = 1.0 ; {{TAGBL|ALDAC}} = 0.0 ; {{TAGBL|AGGAC}} = 0 | ||
#ALGO = D ; TIME = 0.4 | #{{TAGBL|ALGO}} = D ; {{TAGBL|TIME}} = 0.4 | ||
## Leave this in | ## Leave this in | ||
ISMEAR = 0 | {{TAGBL|ISMEAR}} = 0 | ||
SIGMA = 0.01 | {{TAGBL|SIGMA}} = 0.01 | ||
GGA = PE | {{TAGBL|GGA}} = PE | ||
</pre> | </pre> |
Revision as of 13:55, 14 March 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
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