Comment on 'Diatomics-in-molecules calculation of the potential energy surface of H2O+'

Abstract

For original paper see ibid., vol.15, p.L229 (1982). The large discrepancy between a recent diatomics-in-molecules (DIM) and ab initio calculations of the collinear potential energy surface for the reaction O++H2 to OH++H can probably be attributed to the inadequacy of the DIM model in describing the products. Consideration of available ab initio calculations on OH+ suggest that the smallest conceivable DIM model for this reaction must include at least four polyatomic basis functions. The difficulties inherent in comparing the behaviour of different ion-molecule reactions are briefly discussed.