SPIN-RESTRICTED DENSITY-FUNCTIONAL APPROACH TO THE OPEN-SHELL PROBLEM

Open-shell one-electron equations are derived by application of Rootha an's coupling operator technique to the variational procedure of findi ng the Kohn-Sham orbitals and minimizing the energy of an open-shell s ystem, represented within the density functional vector coupling schem e. The final equations are presented in a form suitable for standard q uantum-chemical codes using finite basis set Kohn-Sham calculations. E xamples of multiplets for which the theory is applicable are discussed . (C) 1998 Elsevier Science B.V. All rights reserved.