Towards understanding the origin and nature of the conformational stability of water clusters: A density functional theory and quantum molecular dynamics study

Abstract

To find out what interaction dictates the molecular stability is essential, yet still controversial even for simplest molecules. Here, using water cluster as an example, we employ quantum molecular dynamics to generate a total of 185 conformations for octamer water clusters and then employ two energy partition schemes from density functional theory to pinpoint the principles governing their stability. We found that their stability is strongly correlated with steric repulsion and exchange-correlation interactions. Explanations using two different quantities are also proposed (with the correlation coefficient larger than 0.99). This work sheds light to the fundamental understanding towards the origin and nature of molecular conformational stability for water clusters and other molecular complexes formed through intermolecular interactions. © Editorial office of Acta Physico-Chimica Sinica.