Molecular density functional theory of water including density–polarization coupling

International audienceWe present a three-dimensional molecular density functional theory of water derived fromfirst-principles that relies on the particle’s density and multipolar polarization density andincludes the density–polarization coupling. This brings two main benefits: (i) scalar densityand vectorial multipolar polarization density fields are much more tractable and give morephysical insight than the full position and orientation densities, and (ii) it includes the fulldensity–polarization coupling of water, that is known to be non-vanishing but has never beentaken into account. Furthermore, the theory requires only the partial charge distribution ofa water molecule and three measurable bulk properties, namely the structure factor and theFourier components of the longitudinal and transverse dielectric susceptibilities