On the form of the exact quantum mechanical vibrational kinetic energy operator for penta-atomic molecules in internal coordinates

Abstract

Forms for the exact non-relativistic quantum mechanical vibrational (J = 0) kinetic energy operators for sequentially bonded (A-B-C-D-E) and (A,B)-C-D-E-type penta-atomic molecules, expressed in valence internal coordinates, are presented. As advocated earlier (Handy, N. C., 1987, Molec. Phys., 61, 207), computer algebra has been employed during the derivation. The suggested use of these operators in calculations for vibrational energy levels of interesting penta-atomic molecules (e.g., C3O2, and H2CCO) is outlined.