title: Zero point energy of polyhedral water clusters.
abstract: Polyhedral water clusters (PWCs) are cage-like (H2O)n clusters where every O participates in exactly three H bonds. For a database of 83 PWCs, 8 < or = n < or = 20, geometry was optimized and zero point energy (ZPE) was calculated at the B3LYP/6-311++G** level. ZPE correlates negatively with electronic energy (E0): each increase of 1 kcal/mol in E0 corresponds to a decrease of about 0.11 kcal/mol in ZPE. For each n, a set of four connectivity parameters accounts for 98% or more of the variance in ZPE. Linear regression of ZPE against n and this set gives an RMS error of 0.13 kcal/mol. The contributions to ZPE from stretch modes only (ZPE(S)) and from torsional modes only (ZPE(T)) also correlate strongly with E0 and with each other.
authors.affiliation: Harvard Medical School, McLean Hospital, Centre Building 11, 115 Mill Street, Belmont, Massachusetts 02478, USA. David.Anick@rcn.com
authors.forename: David J
authors.initials: DJ
authors.lastname: Anick
mesh_terms: D000465:Algorithms; D004583:Electrons; D004735:Energy Transfer; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D016014:Linear Models; D010100:Oxygen / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D006859:Hydrogen; D010100:Oxygen