2 NOVEL APPLICATIONS OF SHEPARD-TYPE INTERPOLATION FOR POLYATOMIC SYSTEMS - REDUCED DIMENSIONALITY HOCO AND FULL DIMENSIONALITY AR-HCO

We present potential energy surfaces for two four-atom systems, HOCO a nd Ar-HCO. In the former system a previous, reduced dimensionality 2 d egree-of-freedom model of the OH + CO --> H + CO2 reaction is extended by inclusion of the nonreactive CO stretch. Ln the latter system, ext ensive ab initio calculations are done for 19 HCO geometries and 120-1 50 Ar-HCO planar configurations, for a fixed HCO geometry. Ln both sys tems a Shepard-type representation of the global potential is presente d in the former system in 3 degrees of freedom, and in the latter syst em in the full 6 degrees of freedom. (C) 1997 John Wiley & Sons, Inc.