Potential Energy Surfaces At present, quantum chemists spend much effort in the computation of potential energy (PE) surfaces, and experimentalists utilize these surfaces in their planning of experiments and in their interpretation of experimental results. However, it appears that i t is not generally recognized that all molecules with the same molecular formula (i.e., all molecules in a single formula entry in the Formula Index of Chemical Abstracts) represent local minima on a single PE surface. This conclusion is subject to the assumption that all crossings of P E surfaces are avoided when a "complete" Hamiltanian is used. Additionally, any assemblies of molecules, ions, or complexes between them, lie on the same PE surfaceof their totalmolecular formula, provided the totalcharge is thesame in each. Thus, the surfaceof C3H60(neutral) encompasses not only acetone, propionaldehyde, propylene oxide, and several other stable molecules, hut also many complexes, (e.g., complexes between ethylene and formaldehyde).
C. E. Moore, Allan Banks, and H. H. Jane University of Cincinnati Cincinnati. OH 45221
Volume 64
Number 5
May 1987
395
