Mcsqs for quaternary compound

Alloy Theoretic Automated Toolkit (ATAT)
1

Dear Axel van de Walle,
I am a master student from the Central university, Taiwan. And I am a new user for the `mcsqs’, and here are some questions I want to figure out.
Here is my rndstr.in
5.4353 5.4353 21.6928 90 90 90
1 0 0
0 1 0
0 0 1

0.000000 0.000000 0.000000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.500000 0.000000 Ag=0.25, In=0.25, Zn=0.5
0.243925 0.756075 0.063940 S
0.756075 0.243925 0.063940 S
0.000000 0.500000 0.125000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.000000 0.125000 Ag=0.25, In=0.25, Zn=0.5
0.256075 0.256075 0.186060 S
0.743925 0.743925 0.186060 S
0.000000 0.000000 0.250000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.500000 0.250000 Ag=0.25, In=0.25, Zn=0.5
0.256075 0.743925 0.313940 S
0.743925 0.256075 0.313940 S
0.000000 0.500000 0.375000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.000000 0.375000 Ag=0.25, In=0.25, Zn=0.5
0.243925 0.243925 0.436060 S
0.756075 0.756075 0.436060 S
0.000000 0.000000 0.500000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.500000 0.500000 Ag=0.25, In=0.25, Zn=0.5
0.243925 0.756075 0.563940 S
0.756075 0.243925 0.563940 S
0.000000 0.500000 0.625000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.000000 0.625000 Ag=0.25, In=0.25, Zn=0.5
0.256075 0.256075 0.686060 S
0.743925 0.743925 0.686060 S
0.000000 0.000000 0.750000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.500000 0.750000 Ag=0.25, In=0.25, Zn=0.5
0.256075 0.743925 0.813940 S
0.743925 0.256075 0.813940 S
0.000000 0.500000 0.875000 Ag=0.25, In=0.25, Zn=0.5
0.500000 0.000000 0.875000 Ag=0.25, In=0.25, Zn=0.5
0.243925 0.243925 0.936060 S
0.756075 0.756075 0.936060 S

and the command I used,
mcsqs -2=6 -3=5 ##generated the clusetrs
Corrdump -l=rndstr.in -ro -noe -nop -clus -2=6 -3=5
Vim sqscell.out ##confine the cell
mcsqs -rc -n=60 ##starts calculation

My first question, is there any wrong in the rndstr.in and the command I used?

Second, the command mcsqs -n=60 , doesn’t it mean that I will get a result contain 60 atoms in bestsqs.out? Because I tried the operation above, but I only got a 32 atoms in bestsqs.out. This is very confusing me.

best regard,
Herry

2

Your input file seems fine.
The option -n=60 means "cell of UP TO 60 atoms".
You could manually edit the sqscell.out to keep only the cells you want and then run with the -rc option.

3

Hi Herry,
I am also a new user of ATAT. I was cinfused about the unknow atom positions in the rndstr.in. As presented in the mamual, the input file rndstr.in consist of three parts: unit cell, periodic cell and site, however, the atom positions in the cell is unknow for disorder materials. Where did you get that for you case.

Regards,

L