The interaction of OH(X2Π) with H2: Ab initio potential energy surfaces and bound states

For the interaction of OH(X-2 Pi) with H-2, under the assumption of fixed OH and H2 bond distances, we have determined two new sets of four-dimensional ab initio potential energy surfaces (PES's). The first set of PES's was computed with the multi-reference configuration interaction method [MRCISD+Q(Davidson)], and the second set with an explicitly correlated coupled cluster method [RCCSD(T)-F12a] sampling the subset of geometries possessing a plane of symmetry. Both sets of PES's are fit to an analytical form suitable for bound state and scattering calculations. The CCSD(T) dissociation energies (D-0) of the OH-para-H-2 and the OH-ortho-H-2 complexes are computed to be 36.1 and 53.7 cm(-1). The latter value is in excellent agreement with the experimental value of 54 cm(-1). (C) 2014 AIP Publishing LLC.