A NEW SCHEME FOR THE REDUCTION OF THE EFFECTIVE ROTATIONAL HAMILTONIAN OF A SYMMETRIC TOP-TYPE MOLECULE IN A NONDEGENERATE VIBRATIONAL-STATE

A new scheme for the reduction of the effective rotational Hamiltonian of a symmetric top-type molecule in a nondegenerate vibrational state is considered by means of the example of a molecule with the point symmetry group C3v. As distinct from the traditional scheme, the reduction scheme suggested is possible only with definite limitations on the spectroscopic parameters of the molecule. It is shown that the limitations are fulfilled for the PH3 molecule. It is important that the reduced form obtained has a tridiagonal matrix in the representation of J2, J2. © 1990.