Quantum Calculations on Hydrogen Bonds in Certain Water Clusters Show Cooperative Effects

• DOI: 10.1021/ct600139d
• Publication Date: 2006-12-08T13:01:15Z
• Authors: Vasiliy S. Znamen...; Michael E. Green
• Keywords: Acceptor; Water cluster

Water molecules in clefts and small clusters are a significantly different environment than those bulk water. We have carried out ab initio calculations that demonstrate this series of clusters, showing cooperative effects must be taken into account the treatment hydrogen bonds water such bounded systems. Hydrogen between simulations treated most frequently by using point-charge potentials, as TIP3P or SPC, sometimes with polarizable extension. These produce excellent results water, for which they calibrated. Clefts from bulk; it is necessary to look at smaller systems investigate effect limited numbers neighbors. start study isolated varying neighbors hydrogen-bonded pair molecules. The cluster whole vacuum. defined so provide possible arrangements nearest central then scan length angles bond density functional theory, each arrangement donor acceptor on hydrogen-bonding pair; potential interaction two varies number This also involves changes charge function energy neighboring approximately 6 kBT near room temperature highest lowest when alone varied, enough seriously affect simulations.