Alpha-SiO2

Exercise : C_q du ¹⁷O and screening of Si and O

• INCAR

  SYSTEM      = Si O2

  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     = 0.0 25.5

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       = 30       # to safe memory, ??? = NELECT/2 

• KPOINTS

k-points
 0
gamma
 4  4  4 
 0  0  0

• POSCAR

NiO
 4.17
 1.0 0.5 0.5
 0.5 1.0 0.5
 0.5 0.5 1.0
 2 2
Cartesian
 0.0 0.0 0.0
 1.0 1.0 1.0
 0.5 0.5 0.5
 1.5 1.5 1.5

Download

Ni111clean_400eV.tgz

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