Development of a Flexible Polarizable Water Model

A flexible polarizable water model, DPP2-F, has been developed and its applications to vibrational analysis of water clusters are discussed in this dissertation. The total potential energy function, including intramolecular distortion, point-charge electrostatic, charge penetration, polarization, charge transfer, dispersion and exchange-repulsion contributions, has been evaluated term-by-term with the aid of energy decomposition approach of the Symmetry Adapted Perturbation Theory (SAPT). Detailed error analyses on all potential energy terms are carried out to interpret how the different energy terms balance within the model. The new parameterization scheme improves the water molecular polarizability surface and leads to an increased dipole derivative of the hydrogen-bonded OH stretch. The DPP2-F model successfully predicts the vibrational frequency redshift that happens to the hydrogen-bonded OH vibration, and the appreciation of the vibrational intensity. The magnitudes of these features, however, are severely underestimated by the DPP2-F model. Also included are brief introductions to several other projects undertaken during my graduate study: the ab initio molecular dynamics study on (H5O2)+, the reparameterization of excess electron-water interaction potential, the transition state of (NO2∙H2O)̄, the calculation of vibrational spectra of (H2O)n̄ and [CH3NO2∙(H2O)6]̄