Chemically accurate ab initio potential energy surfaces for the lowest 3A′ and 3A" electronically adiabatic states of O(3P)+H2

The electronic energies of the lowest (3)A' and (3)A " states of the O(P-3) + H-2 system were calculated for 951 geometries using MOLPRO. The calculations were titled by a rotating Morse splint method and independently by a generalized London-Eyring-Polanyi-Sato (LEPS) doubie-polynomial method. A higher accuracy calculation for 112 of these geometries was also performed for both (3)A' and (3)A " to obtain correction potential energy surfaces (PESs) used to raise the accuracy of the original surfaces to about 0.3 kcal/mol. The resulting fitted PESs are presented and compared to each other and to a previous empirical LEPS surface.