DENSITY-FUNCTIONAL CALCULATIONS ON LOW-LYING SINGLY EXCITED-STATES OFOPEN-SHELL ATOMS

By employing a simple density-functional approach, low-lying singly ex cited states of several open-shell atoms, viz. B, C, O, F, Na, Mg, Al, Si, P and Cl, have been calculated and compared with experimental res ults. The work-function-based exchange potential has been used in a no nrelativistic, single-determinantal framework. The effects of two diff erent correlation energy functionals (local Wigner and nonlocal Lee-Ya ng-Parr) on excitation energies and excited-state energies have been s tudied. While the exchange-only results show good agreement with numer ical Hartree-Fock results, the correlation energy functionals do not s how any significant improvements in excitation energies over the excha nge-only results, although the excited-state energies are improved sig nificantly. (C) 1998 Elsevier Science B.V. All rights reserved.