Structural transitions and dipole moment of water clusters (H2O)n=4–100

JULIÁN GELMAN-CONSTANTIN; MARCELO A. CARIGNANO; IGAL SZLEIFER; ERNESTO J. MARCECA; HORACIO R. CORTI

JOURNAL OF CHEMICAL PHYSICS

AMER INST PHYSICS

Año: 2010 p. 245061 - 245068

0021-9606

The properties of water clusters (H2O)n over a broad range of sizes (n=4–100) were studied bymicrocanonical parallel tempering Monte Carlo and replica exchange molecular dynamicssimulations at temperatures between 20 and 300 K, with special emphasis in the understanding ofrelation between the structural transitions and dipole behavior. The effect of the water interactionpotential was analyzed using six nonpolarizable models, but more extensive calculations wereperformed using the TIP4P-ice water model. We find that, in general, the dipole moment of thecluster increases significantly as the cluster melts, suggesting that it could be used to discriminatebetween the solidlike and liquidlike phases. The effect of a moderate electric field on the cluster heatcapacity and total dipole moment was found to be negligible.