Spin spherical harmonics are related to TOTAL angular momentum. They are eigenfunctions of J, Jz
and L, defined as sums of products of orbital and spin wavefunctions:
(θ,φ) = ∑ (ℓ m ½ μ | ℓ ½ j m) Yℓm
where ( ... | ) are Clebsch-Gordan coefficients and χμ
, μ = ±½ are spin states.