Corrected answer
Fe-Ia: two 2-fold rotation axes, one 3-fold rotation axis –> 3-fold rotation axis is the z-axis of the PAS, eta=0
Fe-IIa: two 2-fold rotation axes, one 4-fold rotation axis –> 4-fold rotation axis is the z-axis of the PAS, eta=0
Fe-IIb: two 2-fold rotation axes, one 4-fold rotation axis –> 4-fold rotation axis is the z-axis of the PAS, eta=0