Alpha-AlF3

Exercise : Determine the ¹⁷O C_q value and the Si and O schieldings.

INCAR

SYSTEM = Al F3

  GGA    = PE
  ISTART = 1
  ICHARG = 0
  INIWAV = 1
  LREAL  =  AUTO
  ISYM   = 2
  ISPIN  = 1

Ionic minimisation
  NSW    = 0
  ISIF   = 2
  IBRION = 2
#  EDIFFG = -2E-2
  POTIM  = 0.1

Electronic minimisation
  IALGO = 38

LWAVE  = .TRUE.

 EMIN =   -20.0
 EMAX =   10.0
 NEDOS = 1601

EFG Calculation
LEFG = .TRUE.
QUAD_EFG = 146.6 0.0

Chemical Shift
PREC = Normal    # nice
ENCUT = 400.0      # typically higher cutoffs than usual are needed
ISMEAR = 0; SIGMA= 0.1 # no fancy smearings, SIGMA sufficiently small
EDIFF = 1E-9      # you'd need much smaller EDIFFs.

LCHIMAG = .TRUE.   # to switch on linear response for chemical shifts
DQ = 0.001         # often the default is sufficient
ICHIBARE = 1       # often the default is sufficient
LNMR_SYM_RED = .TRUE. # be on the safe side
NSLPLINE = .TRUE.  # only needed if LREAL is NOT set.
LREAL = A          # helps for speed for large systems, not needed
NBANDS = 25       # to safe memory, ??? = NELECT/2

KPOINTS

automatic mesh
0
Auto
20

POSCAR

Al1 F3
1.0
        4.9305000305         0.0000000000         0.0000000000
        2.4652500153         4.2699382798         0.0000000000
        2.4652650832         1.4233214594         4.1486879977
   Al    F
    2    6
Direct
     0.000000000         0.500000000         0.000000000
     0.500000000         0.000000000         0.500000000
     0.177499995         0.250000000         0.750000000
     0.822499990         0.750000000         0.250000000
     0.677500010         0.322499990         0.250000000
     0.322499990         0.677500010         0.750000000
     0.250000000         0.177499995         0.250000000
     0.750000000         0.822499990         0.750000000

Download

Ni111clean_400eV.tgz

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