In this work we carry out calculations of the long-range interactions between a ground state O atom and a hydrogen molecule at C-s geometries in order to describe the diabatic and adiabatic surfaces that connect the (3)Pi and (3)Sigma states at collinear geometries with the B-3(1), B-3(2) and (3)A(2) states at C-2v configurations. We show that the usual procedure to correct the basis set superposition error gives inconsistent results for the diabatic potentials and their coupling terms. Consistent results can only be obtained using high quality basis sets for which this error can be negligible. (C) 2012 Elsevier B.V. All rights reserved.