Hydrogen bonding in cubic (H2O)8 and OH•(H2O)7 clusters -: art. no. 013204

A systematic study is presented for OH.(H2O)(7) Clusters derived from the cubic (H2O)(8) octamer by replacing one water with a hydroxyl radical. The system is a prototype for atmospheric water clusters containing the environmentally important OH species, and for OH adsorbed at the surface of ice. The full set of 39 symmetry-distinct cubic OH.(H2O)(7) clusters is enumerated, and the structures are determined using ab initio quantum chemical methods. Graph invariants are employed to obtain a unified analysis of the stability and structure of cubic (H2O)(8) and OH.(H2O)(7), relating these physical properties to the various hydrogen-bond topologies present in these clusters. To accomplish this the graph invariant formalism is extended to treat a hydrogen bonding impurity within a pure water network.