Transferability of Atomic Properties in Molecular Partitioning: A Comparison

For a given choice of fragmentation of a molecule, Partition Density Functional Theory (PDFT) provides fragment densities that add up to the correct molecular density, and produce the-in principle exact-molecular energy. Using a simple model system of a heteronuclear diatomic molecule, we investigate the transferability of the resulting PDFT fragment densities by examining how their shapes and dipoles are preserved as the environment changes, and compare with other partitioning schemes. Our results show that (1) the transferability of PDFT densities is about an order of magnitude higher than that of real-space partitioning schemes, and (2) the PDFT dipoles are about an order of magnitude more transferable than Hirshfeld dipoles in regions of chemical relevance.