A new approach to a non-local density functional for the calculation of electron correlation energies

The transition-metal oxides show a range of ground states of broken symmetry; for example, Mott insulators, antiferromagnetic states, charge density waves, and, more recently, high-temperature superconductors. All these properties depend essentially on electronic correlation effects induced by the Pauli effect acting on the double occupation of specific orbitals. Present first principles band theory methods using the local density approximation (LDA) do not converge to an antiferromagnetic ground state for La2-xSrxCuO4 and YBaCuO. In this paper we propose a method based on the Gutwiller projection technique to improve the treatment of the electron correlation. This method requires the reformulation of Bloch waves into localized orbitals about each site as well as a Monte Carlo method for treating the many-body Hamiltonian. We use as input to our many-body formalism the results obtained from a conventional self-consistent ASW augmented spherical wave) band calculation.