A NEW APPROACH TO THE CALCULATION OF SPECTRA FOR STRONGLY CORRELATED SYSTEMS

The possibility of extending finite cluster calculations by setting up an intercluster Hamiltonian, in terms of Hubbard X-operators, and then using renormalization group or generalized mean field approximations is explored. The feasibility of this approach is tested by applying it to the calculation of the one particle Green's function and dynamic susceptibility for the non-degenerate impurity Anderson model. © 1990.