Theor Chim Acta (1989) 76:373-375 Theoretica Chimica Acta 9 Springer-Verlag 1989 Density functional theory calculations of one electron Rydberg states in Li atom M. B. Viswanath and K. D. Sen School of Chemistry, University of Hyderabad, Hyderabad 500 134, India (Received April 28; revised and accepted July 25, 1989) Summary. It is shown by comparison with the available time-dependent coupled Hartree-Fock calculations that the self-interaction-corrected local- spin-density functional theory, with correlation energy, provides an accurate description of the transition energy and the radial expectation values (R- 1) and (R), for the Rydberg states (n =2-8) of Li(ls2nl 1) atom. A simple criterion is proposed to define the percentage of Rydberg character of a valence ns orbital. Key words: Rydberg states -- Atomic Li -- Density functional theory It is well known that an exact treatment of the self-interaction potential within X~-theory [1] leads to a significantly improved description of the various atomic properties [2-6]. Similarly, the self-interaction-corrected local-spin-density (SIC- LSD) approximation with correlation energy has been successfully tested to predict electron affinities of neutral atoms [7-9]. In a recent paper [10] the SIC-LSD calculations of dipole matrix elements have been performed on the Rydberg states of the oxygen atom in the quintet and triplet manifolds, respec- tively, and the results have been found to be in excellent agreement with the corresponding Hartree-Fock results. Since the simplified representation of corre- lation effects is an attractive feature of the SIC-LSD functional theory it would be useful to compare the results of such calculations with a suitable post HF level of calculations which include correlation effects derived from the wave function approach. In this communication we have examined the doublet Rydberg levels of Li within the quasi-relativistic SIC-LSD scheme, with correlation energy, as developed by Perdew and coworkers [7]. In particular, we compare the transition energy, AE, and radial expectation values (R -1) and (R) with the available time-dependent coupled Hartree-Fock (TDCHF) calculations [11]