Solution of the rotation-internal rotation problem of glyoxal type molecules by infinite matrix technique

A numerical solution, using a truncated matrix diagonalization is presented of the rotation-internal rotation problem of a semirigid molecular model consisting of two equivalent tops with C_s local symmetry. Starting from the classical hamiltonian various aspects of the isometrie group of this system are discussed. The coefficient of the energy matrix are calculated analytically and their asymptotic behavior is derived. Furthermore the selection rules and analytical expressions are given for electric dipole transition matrix elements and polarizability tensor matrix elements.