I think if we somehow can ensure an infinitly small energy difference as to make it look like it’s is a continuum spectrum it would look like the classical model. How this can be achieved, i don’t really know though.
Oops i seem to have written this in the wrong forum; this is my answer:
In the cube, there is a 4-fold rotation axis through both Fe-IIb’s. So this can be the z-axis.
There are also two 2-fold rotation axis through the other Fe-IIa. any of these can be chosen as z-axis for the Fe-I.