How to use mcsqs -rc

Alloy Theoretic Automated Toolkit (ATAT)
1

Hi, I would like to randomize a set of atomic species in a supercell without changing the supercell size, shape, or atomic coordinates. I’ve tried the following but obtain a segmentation fault.

  1. Create rndstr.in as a direct copy of a bestsqs.out file from a previous mcsqs run
  2. Edit rndstr.in to specify species to be randomized, i.e. change all ‘Fe’ to ‘Fe=0.5, Co=0.5’
  3. Run ‘corrdump -l=rndstr.in -ro -noe -nop -clus -2=4; getclus’
  4. Create sqscell.out from lines 4-6 of rndstr.in
    1
    1 -2 -2
    2 2 -1
    2 -1 2
  5. Run ‘mcsqs -n=135 -rc’

I also obtain a segmentation fault with sqscell.out:
1
1 0 0
0 1 0
0 0 1
Could you please help me understand what I need to do differently? Thank you!

2

Make sure you are using ATAT version 3.07 or later. (In earlier versions, the cell in sqscell.out had to be given in cartesian coordinates.)
Let me know if you are still having trouble.

BTW, I am not sure what you want to accomplish by randomizing some sites of pre existing SQS…