Dipole Moment Functions of CO and HCl

A general formalism is presented for the least-squares determination of dipole moment functions of diatomic molecules in which the radial part wave functions obtained as numerical solutions of vibration and vibration-rotation Hamiltonian matrix are used. Although this approach is purely numerical, the advantage of using orthonormal basis and perturbed wave functions is retained. Attempts have been made on the determination of the cubic dipole moment functions for the CO and HCl molecules. All the available data of dipole as well as transition moments and the Herman-Wallis factors for these molecules are considered in the refinement process. The following cubic dipole moment functions are obtained (in Debye): M(Δr)=0.1243–3.0722(Δr)+0.1909(Δr)2+2.1856(Δr)3 for CO and M(Δr)=1.093+0.949(Δr)+0.034(Δr)2–0.78(Δr)3 for HCl.