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Electron poor materials research group. Group meeting Sept. 30, 2010 Theory-FCC Zinc-Blende Equations of State. Procedure. 20 Volume cycles each volume cycle contains 3 VASP runs 2 relaxation runs (back to back) and then a static run to get accurate energy values
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Electron poor materials research group Group meeting Sept. 30, 2010 Theory-FCC Zinc-Blende Equations of State
Procedure • 20 Volume cycles • each volume cycle contains 3 VASP runs • 2 relaxation runs (back to back) and then a static run to get accurate energy values • all 20 cycles take from 3-6 minutes • Values for the minimum volume V0, bulk modulus K0, minimum energy E0, and derivative of the bulk modulus K0p are then calculated from a 3rd order Birch-Murnaghan fit to the 20 volume and free energy points obtained from the 20 Volume cycles.
INCAR_relax System = InSb NSW = 5 | number of ionic steps ISIF = 4 | ISIF=4 relax cellshape and ions. NOT volume IBRION = 1 | ionic relaxation algorithm EDIFF = 1E-4 | break condition for elec. SCF loop EDIFFG = -1E-3 | break condition for ionic relaxation loop MAXMIX = 80 | keep dielectric function between ionic movements NELMIN = 8 | minimum number of electronic steps NFREE = 15 | number of degrees of freedom (don't go above 20) #RECOMMENDED MINIMUM SETUP GGA=CA #xchange-correlation VOSKOWN=0 #=1 if GGA=91; else = 0 PREC = NORMAL #PRECISION, sets fft grid ENCUT = 150 #energy cutoff, commented to use enmax in potcar LREAL = .FALSE. #.FALSE. MEANS USE RECIPROCAL LATTICE ISMEAR = 0 #0 means use gaussian smearing
INCAR_static System = InSb #ISTART = 0 # startjob: no WAVECAR file #ICHARGE = 2 # charge: from atoms #INIWAV = 1 # random initialization for wf. NELM = 40 # maximum of 40 electronic steps NELMIN = 2 # minimum of 2 steps NELMDL = -5 # no update of charge for 3 steps EDIFF = 1E-4 # accuracy for electronic minimization #RECOMMENDED MINIMUM SETUP GGA=CA #xchange-correlation VOSKOWN=0 #=1 if GGA=91; else = 0 PREC = NORMAL #PRECISION, sets fft grid ENCUT = 150 #energy cutoff, commented to use enmax in potcar LREAL = .FALSE. #.FALSE. MEANS USE RECIPROCAL LATTICE ISMEAR = -5 #-5 means use tetrahedral with blochl
InSb Experimental Volume: 67.97
GaSb Experimental Volume: 56.63
ZnTe Experimental Volume: 56.83
ZnSe Experimental Volume: 45.98