Local embedding potentials for strongly correlated molecules.

Reaching chemical accuracy on the interaction energy between subsystems in quantum embedding methods remains an important challenge for electronic-structure theory. An intriguing question for density embedding methods that are grounded in the Hohenberg-Kohn theorem is whether a local and multiplicative embedding potential is sufficient to capture effects like strong correlation and entanglement between subsystems. Here, we investigate this question by applying Partition Density Functional Theory to molecules known for strong correlation, charge transfer, and engineered entanglement, using multi-configurational wavefunctions as a reference. We demonstrate that a unique, local partition potential can be found in all cases, and provide numerical evidence that the local potential framework in density embedding is capable of handling these traditionally difficult problems.