Chemical Shifts in Liquid Water Calculated by Molecular Dynamics Simulations and Shielding Polarizabilities

The gas-to-liquid chemical shifts of water have been calculated by combining molecular dynamics simulations and quantum chemically derived shielding polarizabilities. The use of a force field based on intermolecular perturbation theory ensures that the electric fields are adequately modeled. The experimental proton shift and its temperature dependence are reproduced, but the oxygen shift lacks higher order terms such as the linear field-gradient contribution. Shifts arising from the difference in the gas phase and liquid geometries of the water molecule have been estimated and discussed.