where 𝐴 ,ℓ are the eigenvector coefficients from the point dipole matrix in eqn (12). Unlike the magnitude of orbital angular momentum, its projection onto the dipole axis (represented by the quantum number λ) is still a conserved quantity. In the limit of zero dipole moment, the freeparticle and point-dipole approaches become identical and 𝐿 correlates with a particular ℓ, λ combination. Thus, the index N can be correlated with a zero-dipole-limit ℓ quantum number.