Equations‐of‐motion method: Calculation of the k lowest or highest solutions
Jean‐Pierre Flament, H.P. Gervais · International Journal of Quantum Chemistry · 1979
Abstract The method of optimal relaxation to determine the eigenvalues of symmetric matrices, as proposed by Shavitt, has been adapted to solve the equation‐of‐motion problem. Matrices Z and Y are obtained by one diagonalization, while matrices A and B remain unchanged. This procedure is particularly useful for high‐dimensional or nonorthogonal bases, if one needs only the lowest transition energies.