The Dipole Polarizability of a Water Molecule \textit{in} Liquid Water

The dipole polarizability, $\alpha$, provides a measure of the tendency of a molecule or material to deform (or polarize) in the presence of an electric field. Within the framework of density functional theory (DFT), we present a hierarchy of first principles based approaches for computing $\alpha$ of a molecule located in the condensed phase. This hierarchy includes a successive treatment of both short-range (hybridization, Pauli exchange-repulsion, etc.) and long-range (Coulomb) electrodynamical response screening in the computation of $\alpha$, while simultaneously accounting for the surrounding condensed-phase environment. Utilizing highly accurate liquid water configurations generated from van der Waals inclusive hybrid DFT based \textit{ab initio} molecular dynamics, we computed $\alpha$ for a given water molecule \textit{in} liquid water as a first application of this approach. Our findings will be compared and contrasted with $\alpha$ computed for an isolated gas-phase water molecule.