Calculation of the Hubbard-Type Many Body Interaction Parameters Using Constrained Density Functional Theory

Many theoretical models for highly correlated electron systems are based on some form of the Hubbard model Hamiltonian. In its generalized form this Hamiltonian contains Coulomb interaction parameters for electrons localized on the same site or on neighboring sites in the lattice. The energy cost associated with charge fluctuations is screened in the solid by all electronic degrees of freedom not explicitly included as dynamic variables in the model.