Accurate CH+ ab initio potential energy curves were calculated. The quality of the potentials was checked by comparing experimental and calculated CH+ absorption cross-sections for various rotational transitions. The relative importance of couplings and corrections to the Born-Oppenheimer approximation was studied. When relativistic corrections were included and core electrons also correlated, good agreement was achieved between the experiment and the theory for the photodissociation cross-section. The new potentials were used to calculate the radiative association cross-section. (C) 2004 Elsevier B.V. All rights reserved.