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Electron poor materials research group

Electron poor materials research group. Group meeting Dec 2, 2010 Theory- VASP simple GW calculations on Si and GaAs. Procedure. Perform a static calculation on the target structure. Take the WAVECAR WAVEDER and CHGCAR from the static calculation and then execute the GW calculation.

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Electron poor materials research group

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  1. Electron poor materials research group Group meeting Dec 2, 2010 Theory- VASP simple GW calculations on Si and GaAs

  2. Procedure • Perform a static calculation on the target structure. • Take the WAVECAR WAVEDER and CHGCAR from the static calculation and then execute the GW calculation. • These runs were done on saguaro using 16 processors. • KPOINT grid: 6X6X6 gamma • Number of Bands: 150

  3. INCAR_static System = Si SIGMA = 0.01 #RECOMMENDED MINIMUM SETUP PREC = NORMAL #PRECISION ENCUT = 320 #LREAL = .FALSE. #.FALSE. MEANS USE RECIPROCAL LATTICE ISMEAR = 0 #USE GAUSSIAN SMEARING LOPTICS = .TRUE. NBANDS = 150

  4. INCAR_gw System = GaAs SIGMA = 0.01 #RECOMMENDED MINIMUM SETUP PREC = NORMAL #PRECISION ENCUT = 320 #LREAL = .FALSE. #.FALSE. MEANS USE RECIPROCAL LATTICE ISMEAR = 0 #USE GAUSSIAN SMEARING LOPTICS = .TRUE. NBANDS = 150 ALGO = GW0 NOMEGA = 64 NELM = 4 PRECFOCK=N LSPECTRAL=.TRUE.

  5. Si - Automatically Generated KPOINTS

  6. Si - GW stats, a look at the bandgap • GW run time: 68m6.3s • The average difference between the valence and conduction band in the DFT is: 3.771 eV. Using GW the difference is 4.535 eV. ΔE=4.535 - 3.771 eV = 0.7644. • The Si bandgap according to DFT is Eg= 0.5797 eV. • New Gap = ΔE + Eg = 1.344 eV ??

  7. GaAs - Automatically Generated KPOINTS

  8. GaAs - GW stats, a look at the bandgap • GW run time: 58m13.1s • The average difference between the valence and conduction band in the DFT is: 3.750 eV. Using GW the difference is 4.514 eV. ΔE=4.514 - 3.750 eV = 0.7634. • The GaAs bandgap according to DFT is Eg= 0.6035 eV. • New Gap = ΔE + Eg = 1.367 eV ??

  9. Kresse - GW in semiconductor, a reference PHYSICAL REVIEW B 75, 235102 2007

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