The ABINIT Users Mailing List ( CLOSED )

[ren <opticalcase@gmail.com>]

Dear All,

I am using Cell2Abinit.py to transform a 2x2x2 supercell of ZnO from
Castep to Abinit format. I suppose that the transformation creates a
primitive cell? The problem occurs when I am trying to run Abinit, the
calculation halt and the log file says

" According to the symmetry finder, the unit cell is
  NOT primitive. The multiplicity is  8 .
  The use of non-primitive unit cells is allowed
  only when the input variable chkprim is 0.
  Action : either change your unit cell (rprim or angdeg),
  or set chkprim to 0. it says that the input structure is not a
primitive cell and has a multplicity of 8."

While I input chkprim = 0 and the calculation continues run may I know if

1) It is appropriate just to simply use chkprim = 0

2) Is there something i have miss out while using Cell2Abinit that the
output is not a primitive cell in the end? My structure input is as
below:

####################################################
# Atoms Stucture created by CellToAbinit Converter !
####################################################

# Definition of the unit cell
#The length of the primitive vectors
#                    1 Bohr=0.5291772108 Angstroms
# acell 5.627901 6.498540 10.410880 Angstroms
acell 10.635191 12.280461 19.673712
rprim
    1.000000  -0.577350  0.000000
    0.000000  1.000000  0.000000
    0.000000  0.000000  1.000000

#Definition of the atom types
#      32 kind of atoms
#       ['O', 'Zn']
ntypat  2
znucl  8 30

#Definition of tha atoms
natom  32
typat  1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
xred
   0.166667 0.333333   0.1913
   0.333333 0.166667   0.4413
   0.666667 0.333333   0.1913
   0.833333 0.166667   0.4413
   0.166667 0.833333   0.1913
   0.333333 0.666667   0.4413
   0.666667 0.833333   0.1913
   0.833333 0.666667   0.4413
   0.166667 0.333333   0.6913
   0.333333 0.166667   0.9413
   0.666667 0.333333   0.6913
   0.833333 0.166667   0.9413
   0.166667 0.833333   0.6913
   0.333333 0.666667   0.9413
   0.666667 0.833333   0.6913
   0.833333 0.666667   0.9413
   0.166667 0.333333      0.0
   0.333333 0.166667     0.25
   0.666667 0.333333      0.0
   0.833333 0.166667     0.25
   0.166667 0.833333      0.0
   0.333333 0.666667     0.25
   0.666667 0.833333      0.0
   0.833333 0.666667     0.25
   0.166667 0.333333      0.5
   0.333333 0.166667     0.75
   0.666667 0.333333      0.5
   0.833333 0.166667     0.75
   0.166667 0.833333      0.5
   0.333333 0.666667     0.75
   0.666667 0.833333      0.5
   0.833333 0.666667     0.75

##### End of CellToAbinit Conveter ! #####

The calculation runs well for a 1x1x1 and 3x3x3 cell without such
these comment though.

Would like to hear your advises!

Regards,

Yee Yan, Tay

Nanyang Technological University

Singapore