On the rapid computation of matrix elements

Abstract

Abstract A method is presented for evaluating the overlap contribution to matrix elements over Slater determinantal wave functions formed from products of nonorthogonal spin orbitals. The method utilizes the overlap cofactor formulation for matrix elements. Prescriptions are given for rapid computation of the necessary cofactors. The method is particularly well suited to the evaluation of integrals over one‐, two‐, and three‐electron operators, such as are encountered in conventional configuration interaction calculations, density matrix evaluations, calculations using functions of interelectronic coordinates, etc.