In principle, one may also introduce a (possibly complex) phase factor in the definition of C ± ± ( j , m ) . The choice made in this article is in agreement with the Condon–Shortley phase convention. The angular momentum states are orthogonal (because their eigenvalues with respect to a Hermitian operator are distinct) and are assumed to be normalized, ⟨ ⟨ j m | j ′ m ′ ⟩ ⟩ = δ δ j , j ′ δ δ m , m ′ .