The electrostatic properties of water molecules in condensed phases: an abinitio study

Ab initio calculations are reported for water molecules in several condense d phases, looking particularly at the electrostatic properties of individua l molecules. The approach is based on the flux of the electron density grad ient to identify the electron distribution of individual molecules. Molecul ar dipole and quadrupole moments are calculated for molecules in a variety of environments, using configurations generated from classical and ab initi o molecular dynamics simulations at 300K. These make it possible to charact erize differences between classical models and ab initio calculations with both fixed and varying molecular geometry. Our main result is an estimate o f the average dipole and quadrupole moments for the water molecule in liqui d and solid phases.