Structural Fluctuation of a Protonated Water Cluster

In the present study we adopt a dissociable and polarizable potential model to simulate how a protonated water cluster H+(H2O)8 structure changes over different levels of temperature. Potential energy plays a major role in defining the configuration of the molecular cluster. For the lowest temperature we examined, 20 K, generated structures by the simulation are dominated by a flowerlike structure, in line with the structure of the known minimum energy configuration for the H+(H2O)8 cluster. As temperature increases, the structure changes to more open ones, complemented with single ring characteristic. In higher temperature the ring decreases in size, indicating tendency to be more open as temperature rises. At the highest examined temperature, 260 K, treelike structures instead dominate the cluster. Each kind of structure corresponds to a certain range of potential energy. Higher temperature contributes to higher potential energy, thus confirming that higher potential energy corresponds to more open structures, or longer range of molecular configuration