Symmetry of the Wave Functions in the Band Theory of Ferromagnetic Metals

Abstract
The symmetry of wave functions in the one-electron band theory of ferromagnetic solids is discussed. The exchange interaction, spin-orbit coupling, and coupling of spins to the magnetic induction vector B are included in the Hamiltonian. The resulting symmetry, which is not invariant under time reversal, can contain only those point operations which belong to the paramagnetic space group and leave the pseudo-vector B invariant at the same time. Character tables are presented for the case of face-centered cubic, body-centered cubic, and hexagonal close-packed structures and for various directions of B. Compatibility relations and lifting of degeneracies are discussed.