Diffusive grain-surface chemistry involving the atoms and diatomic molecules of two elements J. G. L. Rae, N. J. B. Green, T. W. Hartquist, M. J. Pilling and T. Toniazzo A&A, 405 2 (2003) 387-396 Published online: 19 June 2003 DOI: 10.1051/0004-6361:20030415