THE CONVERGENCE PROPERTIES OF HINDERED ROTOR ENERGY-LEVELS

The Schrodinger equation describing one-dimensional hindered rotation of one CHO group against the other in glyoxal is solved variationally using three sets of basis functions and an experimentally derived pote ntial taken from the literature. Reference states are defined by the f ree rotor potential, a single well potential and a double well potenti al. Of the basis sets studied, the double well reference states provid e the most rapidly convergent reference functions for solving the full hindered rotor Hamiltonian. In the case of the free rotor and double well reference states, unusual patterns to convergence were observed f or the cis levels. (C) 1997 Published by Elsevier Science B.V.