The Fe-I atom has a vertical symmetry axis which is 4-fold, the èta will thus be 0 at this point. Furthermore it has 2 2-fold axes which are orthogonal and situated in the horizontal plane.
The Fe-II atom has a vertical symmetry axis which is 4-fold, the èta will thus be 0 at this point. Furthermore it has 2 2-fold axes which are orthogonal and situated in the horizontal plane.
The PAS has in both cases it’s z-axis vertically alligned.