In this paper, we analyze the topological factors which play a role on the energetic distribution on the products of a three-atom indirect reaction: A + BC → AB + C. In order to realize a systematic investigation we built an analytical expression for model surfaces exhibiting a well along the route from reactants to products. With the help of the one-dimensional quasi-classical trajectory approach, it has been found that the anisotropy of the well is a dominant factor which governs the final distribution between the vibration of the newly formed diatomic molecule AB and the relative translation between C and AB.