This code requires 3 input files:
1) A lattice file (by default lat.in) in the same format as for
maps or corrdump.
2) A cluster file (by default clusters.out), as generated with
the corrdump utility.
3) A target correlation file (by default tcorr.out) which
contains the value of desired correlations for each of
the clusters listed in the cluster file.
A typical caling sequence would be:
# the following command can be used to generate the target correlation file tcorr.out
corrdump -noe -2=maxradius -rnd -s=conc.in > tcorr.out
# where maxradius is the length of the longest pair desired
# and where conc.in contains an (ordered) structure having the
# desired concentration.
# The geometry of the structure in the conc.in file is basically ignored
# only its concentration will be used.
#this looks for possible sqs of 8 atoms/ cell
gensqs -n=8 > sqs8.out
corrdump -2=anotherradius -3=anotherradius -noe -s=sqs8.out
# this helps you decide which sqs is best based on other correlations
# associated with clusters (pairs and triplets) of diamter less than
# anotherradius.
Caution:
gensqs only generates structures containing exactly the number of atoms per unit cell specified by the -n option.
(If an SQS with a smaller unit cell exists, it will not be listed.)
If you give too many correlations to match, the code may not
output anything.
Finding an 8-atom sqs takes a few minutes, an 16-atom sqs, a few hours
and a 32-atom sqs, a few days!
The exact speed depends on the symmetry of the lattice and on your
computer.