Dear all,
I am currently trying to study the system (MnCoGe)_{1-x}(NiCoGe)_x, with x being around 11-12%. This is what my rndstr.in looks like:
5.894 3.798 7.035 90 90 90
1 0 0
0 1 0
0 0 1
0.152500004 0.250000000 0.583199978 Co
0.847499967 0.750000000 0.416800022 Co
0.347499996 0.750000000 0.083199978 Co
0.652500033 0.250000000 0.916800022 Co
0.032099999 0.250000000 0.198799998 Mn=0.883333333,Ni=0.116666667
0.967899978 0.750000000 0.801200032 Mn=0.883333333,Ni=0.116666667
0.467900008 0.750000000 0.698799968 Mn=0.883333333,Ni=0.116666667
0.532100022 0.250000000 0.301200002 Mn=0.883333333,Ni=0.116666667
0.774200022 0.250000000 0.620400012 Ge
0.225799978 0.750000000 0.379599988 Ge
0.725799978 0.750000000 0.120400012 Ge
0.274200022 0.250000000 0.879599988 Ge
As you can see, I wanted to start with volume 5 supercell, i.e. 60 atoms, with a Ni occupancy of 7/60~0.116666667 on the Mn site.
After first generating clusters [mcsqs -2=6 -3=6],
2 3.03377 4
2 3.40195 4
2 3.79800 4
2 4.65930 4
2 4.75150 8
2 4.86092 8
2 5.19974 8
2 5.89400 4
3 3.79800 4
3 4.65930 4
3 4.75150 8
3 4.75150 4
3 4.75150 8
3 4.75150 4
3 4.86092 8
3 4.86092 8
3 4.86092 8
3 4.86092 8
3 5.19974 8
3 5.19974 4
3 5.19974 8
3 5.19974 8
3 5.19974 8
3 5.19974 4
3 5.89400 4
3 5.89400 8
3 5.89400 8
3 5.89400 8
I am now getting the "Impossible to match point correlations due to incompatible supercell size." message when I submit [mcsqs -n=60] for a 60-atom supercell.
I wonder if this is because 0.116666667 is not exactly 7/60? Is there some way to deal with this or is there another reason this supercell size is not sufficient?
Update: I found an error in my initial rndstr.in (I have updated it above), and now it seems as though [mcsqs -n=180] may work. My updated question is now: why is the 60 atom supercell not sufficient? And is there a way to examine the same x value with a smaller supercell (perhaps I am using too many clusters)?
Any help is appreciated.