Proper treatment of symmetries and excited states in a computationally tractable Kohn-Sham method

A new Kohn-Sham (KS) formalism, the symmetrized generalized adiabatic conne ction KS formalism, is introduced. It is applicable to ground as well as ex cited states and does not suffer from the symmetry problems of the standard KS approach. In all cases a totally symmetric, non-spin-polarized KS Hamil tonian operator arises. Complete electronic spectra, including multiplet sp littings, Rydberg series, and x-ray and Auger data can be described. Result s for the carbon atom and the carbon monoxide molecule are presented.