The ABINIT Users Mailing List ( CLOSED )

[blesgen@mis.mpg.de]

Dear ABINIT users,

I would like to do computations for tetragonal chalcopyrite (CuFeS_2),
spacegroup 122 = I-42d. Unfortunately I have problems to set up the geometry.

I chose as parameters

acell 5.2864 5.2864 5.2051 angstrom

rprim 1.0  0.0  0.0    #translations in dimensionless form
      0.0  1.0  0.0
      0.5  0.5  0.5
ntypat 3               # There are three types of atoms, Cu, Fe and S
znucl 29 26 16         # refers to the atomic number of the atoms
xred                   # location of atoms
   0.0   0.0  0.0      # Triplet giving the REDUCED coordinate of atom 1 (Cu)
   0.0   0.0  0.5      # Triplet giving the REDUCED coordinate of atom 2 (Fe)
   0.257 0.25 0.125    # Triplet giving the REDUCED coordinate of atom 3 (S)

I also tried acell 5.2864 5.2864 10.4102 angstrom and/or xred 0.25 0.25 0.125
for atom3.The parameters presented above agree with known data for 
chalcopyrite 
taken from http//cst-www.nrl.navy.mil/lattice.

ABINIT doesn't recognize the space group, thinking it is primitive triclinic
(spacegroup 1) or fc monoclinic (spacegroup 8). Probably only some digits are
wrong, but I have no idea. Also I am not so sure how to set up KPTRLATT in
my case.

It would be very kind if some more experienced user than myself could look 
into
this and help me with my problem.

Best regards,

Thomas Blesgen
Max-Planck-Institute for Mathematics in the Sciences (MIS)
Leipzig
Germany