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[wxw079000@utdallas.edu]

Dear all,

I calculated the InAs energy gap with LDA method(ABINIT 5.4.4 VERSION, PHI 
USPP). From my calculations, the energy gap is 0 eV whatever I changed the 
lattice constants, tsmear value from 0.01~0.5, kpoints (2x2x2,4x4x4,6x6x6). 
That's a very strange issue. On the constray, the energy gap changed when I 
changed the parameters above with VASP calculation. Is there any kind person 
to help me check the input file? The following is the input file, please 
check it out.

Best wishes,

Weichao,Wang

#####################
####input file ######
kptopt   1            # Option for the automatic generation of k points
ngkpt    4 4 4        # Density of k points

# Definition of the k-point grid
nkpt   10 
nshiftk  4 
shiftk  0.0 0.0 0.0  # This grid is the most economical
         0.5 0.0 0.0
         0.0 0.5 0.0
         0.0 0.0 0.5
prtden  1         # Print out density
acell  3*11.450        # This is equivalent to   10.217 10.217 10.217
rprim  0.0  0.5  0.5   # FCC primitive vectors (to be scaled by acell)
       0.5  0.0  0.5
       0.5  0.5  0.0

# Definition of the atom types
ntypat  2         # There is only one type of atom
znucl 49 33       # The keyword "znucl" refers to the atomic number of the 
                  # possible type(s) of atom. The pseudopotential(s) 
                  # mentioned in the "files" file must correspond
                  # to the type(s) of atom. Here, the only type is Silicon.

# Definition of the atoms
natom 2           # There are two atoms
typat  1 2        # They both are of type 1, that is, Silicon.
xred              # Reduced coordinate of atoms
      0.0  0.0  0.0
      0.25 0.25 0.25

# Definition of the planewave basis set (at convergence 16 Rydberg 8 Hartree)
ecut 5.0          # Maximal kinetic energy cut-off, in Hartree

# Use only symmorphic operations
symmorphi 0
  ccopt 3    # treat it as metal
  tsmear 0.01

nstep   60        # Maximal number of SCF cycles
diemac  10.00     # Although this is not mandatory, it is worth to
                  # precondition the SCF cycle. The model dielectric
                  # function used as the standard preconditioner
                  # is described in the "dielng" input variable section.
                  # Here, we follow the prescription for bulk silicon.
tolwfr  1.0d-6

# This line added when defaults were changed (v5.3) to keep the previous, old 
behaviour
  iscf 7
  ixc 7 7

######################################3
######################################
#########################