Effective Vibrational-Rotational Hamiltonian and the Potential Surface

A method for studying the potential surfaces of polyatomic molecules is developed in the context of the theory of effective Hamiltonians. Simple iterative schemes for determining equilibrium coordinates of nuclei and points of the closest approach of electronic surfaces are derived in the form of closed systems of equations. The influence of intramolecular interactions on the potential surface is studied to the second order in perturbation theory.