Fig. 5.

Electronic structure of manganese chalcogenophosphates from density functional theory (DFT) calculations. (A) The band structures of MnPX₃ (X = S, Se) near the band gaps. The energy scales are zeroed to the Fermi level. (B) The momentum-resolved degrees of circular polarization of MnPX₃ (X = S, Se), η^(s)(k), between the top of valence bands and the bottom of conduction bands. Only the values of one spin are presented, as in our calculations the other spin takes values equal in magnitude but with opposite signs over the Brillouin zone. At Γ, the computed optical selectivity is nonzero. This is a numerical artifact because of indeterminacy in η^(s)(k) in the presence of band degeneracy (apart from the spin degeneracy) in the valence bands (A).