Algebra

Angular algebra in arc.wigner

CG(j1, m1, j2, m2, j3, m3)	Clebsch–Gordan (CG) coefficients
Wigner3j(j1, j2, j3, m1, m2, m3)	Evaluates Wigner 3-j symbol
Wigner6j(j1, j2, j3, J1, J2, J3[, verbose])	Evaluates Wigner 6-j symbol
WignerDmatrix(theta, phi[, gamma])	WignerD matrices for different j states in a specified rotated basis.