  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.
