  We classify the 3-point functions of local gauge-invariant single-trace
operators in the scalar sector of planar N=4 supersymmetric Yang-Mills
involving at least one su(3) operator. In the case of two su(3) and one su(2)
operators, the tree-level 3-point function can be expressed in terms of scalar
products of su(3) Bethe vectors. Moreover, if the second level Bethe roots of
one of the su(3) operators is trivial (set to infinity), this 3-point function
can be written in a determinant form. Using the determinant representation, we
evaluate the structure constant in the semi-classical limit, when the number of
roots goes to infinity.
