ABINIT Discussion Forums

PLEASE HELP ME, i want to calculate GS of Ca(0.75)Ba(0.25)B6, i want to have supercell of 32 atoms . What i am trying to do is doping of CaB6, my questions are as follows i dont know how to write my xred because i dont know how to get the atomic positions of my doped system, second question is what will be my mixchal input and i want all to assist in correcting my input file.
This is my input file,
############################################################
# GS of Ca(0.75)Ba(0.25)B6
############################################################

#Datasets: etotal vs acell
ndtset 14 acell: 3*7.50 acell+ 3*0.05

ionmov 3 # Use the modified Broyden algorithm
ntime 10 # Maximum number of Broyden "timesteps"
tolmxf 5.0d-4 # Stopping criterion for the geometry optimization : when
# the residual forces are less than tolmxf, the Broyden
#Basis definitions
ecut 95.
ecutsm 0.5
# pawecutdg 24.
#K-points and sym
nsym 0
occopt 1
ngkpt 4 4 4
nshiftk 1
shiftk 0.5 0.5 0.5

#I/O parameters
optforces 2 optstress 1
prtwf 1 prtden 0 prteig 0
getwfk -1
#Definition of the SCF procedure
nstep 150 # Maximal number of SCF cycles
toldfe 1.0d-6 # Will stop when, twice in a row, the difference
# between two consecutive evaluations of total energy
# differ by less than toldfe (in Hartree)
# This value is way too large for most realistic studies of materials
diemac 12.0 # 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.
# tolvrs 1.0d-10
nband 16
# add to conserve old < 6.7.2 behavior for calculating forces at each SCF step



#COMMON INPUT DATA###########################################################
#
# CaB6 lattice structure
npsp 3
ntypat 3
ntypalch 1
mixalch 1 0.25
#ntyppure 1
znucl 5 20 56
natom 8
typat 1 2 2 2 2 2 2 3

#Definition of the unit cell
#acell 3*8.1
angdeg 90 90 90
spgroup 221

# Atomic positions
xred 0.00 0.00 0.00 #Ca1
0.50 0.50 0.20 #B2
0.50 0.50 -0.20 #B2
0.50 0.20 0.50 #B2
0.50 -0.20 0.50 #B2
0.20 0.50 0.50 #B2
0.80 0.50 0.50 #B2
0.00 0.00 0.10 #Ba3

ixc 11
timopt 2
At all, thanks for your usuall assistance.