Structure constants for rational conformal field theories

Exploiting the associativity of the operator product algebra, we obtain the structure constants for the affine SU(2) complementary and exceptional series, uniquely determined in terms of the diagonal ones. The result extends to the non-diagonal unitary minimal series with c<1. We investigate the more general cases of class I (extended diagonal) and class II (non-diagonal) algebras and find a relation between them based on the symmetries of their fusion rules.