Potential energy curves and coupling matrix elements of the one-electron capture by Mg2+ ions in collision with Zn atoms have been determined at the multi-reference configuration interaction level of theory. The cross sections calculated using a semi-classical approach in the [1-300] keV laboratory energy range are in good agreement with the experimental measurements and reflect the importance of the molecular description. (C) 2009 Elsevier B.V. All rights reserved.