Fuzzy atoms in molecules from Bregman divergences

We define the densities of atoms in molecules so that their Bregman divergence from reference proatom densities is minimized. This generalizes the information-theoretic approach to atoms in molecules and under reasonable assumptions, results in a formulation that resembles the Hirshfeld partitioning. In general, Bregman partitionings are intrinsically nonlocal, and this means that this formulation, while mathematically elegant, is computationally unwieldy.