Towards the Kantorovich dual solution for strictly correlated electrons in atoms and molecules

The many-body Coulomb repulsive energy of strictly correlated electrons provides direct information of the exact Hohenberg-Kohn exchange-correlation functional in the strong interaction limit. Until now the treatment of strictly correlated electrons is based on the calculation of co-motion functions with the help of semi-analytic formulations. This procedure is system specific and has been limited to spherically symmetric atoms and strictly 1D systems. We develop a nested optimization method which solves the Kantorovich dual problem directly, and thus facilitates a general treatment of strictly correlated electrons for systems including atoms and small molecules.