IMPORTANT NOTE: Please see mcsqs command for a better, easier-to-use SQS generator. 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 not crucial - # only the average concentration on each sublattice will be used. # CAUTION: Here, a 'sublattice' is a set of symmetrically equivalent point clusters. # If your system contains multiple sublattices (as evidenced by multiple # point clusters in clusters.out, make sure that your conc.in file sets # the composition of each sublattice correctly! This can be verified # by looking at the point correlations output. #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.