We investigate geometric corrugation for D-2 dissociation on Pt( 1 1 1) by mapping the dependence of the initial reaction probability on incident kinetic energy and polar angle for two different azimuths. In accordance with predictions from dynamical calculations of dissociation on an SRP-based potential energy surface, we find at most a very weak signature of geometric corrugation at large polar angles. (C) 2018 The Authors. Published by Elsevier B.V.