  An interacting lattice model describing the subspace spanned by a set of
strongly-correlated bands is rigorously coupled to density functional theory to
enable ab initio calculations of geometric and topological material properties.
The strongly-correlated subspace is identified from the occupation number band
structure as opposed to a mean-field energy band structure. The self-consistent
solution of the many-body model Hamiltonian and a generalized Kohn-Sham
equation exactly incorporates momentum-dependent and crystal-symmetric
correlations into electronic structure calculations in a way that does not rely
on a separation of energy scales. Calculations for a multiorbital Hubbard model
demonstrate that the theory accurately reproduces the many-body polarization.
