Initially state-selected cross sections and thermal rate constants for the reaction CN+H-2--> HCN+H have been calculated using a mixed quantum-classical method: the vibrations of the two reagents are treated quantum mechanically by means of an exact solution of the time-dependent Schrodinger equation, while translational and rotational motions are treated classically. Coupling between quantum and classical degrees of freedom is realized within an effective Hamiltonian approach. (C) 2000 American Institute of Physics. [S0021-9606(00)00138-0].