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.