Dear ATAT users,
I have obtained through mmaps the relevant ECIs (eci.in) with their respective clusters, for a system with the following lattice symmetry (lat.in)
6.0 6.0 6.0 90 90 90
1.0 0.0 0.0
0.0 1.0 0.0
0.0 0.0 1.0
0.0 0.0 0.0 Ge
0.0 0.5 0.5 Ge
0.5 0.0 0.5 Ge
0.5 0.5 0.0 Ge
0.25 0.25 0.25 X, Y
0.25 0.75 0.75 X, Y
0.75 0.25 0.75 X, Y
0.75 0.75 0.25 X, Y
0.75 0.75 0.75 A, B
0.75 0.25 0.25 A, B
0.25 0.75 0.25 A, B
0.25 0.25 0.75 A, B
As you see, X and Y form a pair of exchangeable atoms for 4 different lattice sites, while A and B form a second pair for other 4 different lattice sites. My question is: How can I know the pseudospin values used for ATAT for these two pairs of atoms? In the simplest case, (let’s say for X an Y) it can be assigned -1 and 1. If I get it right, in principle the pseudospins should form and orthonormal basis. Where can I checked the basis used by the cluster expansion?
Thank you very much!