Discrete-continuum interactions in Cl i and S i

McGuire [ J. Opt. Soc. Am.69, 525– 532 ( 1979)] has argued that an earlier configuration-interaction calculation by one of us on the position of Cl i 3s3p6 2S is “fundamentally incorrect” and that the agreement between the results of our calculation and those of a multiconfiguration Hartree–Fock calculation is fortuitous. McGuire furthermore predicts that the two methods will give different answers for the position of S i 3s3p5 3P∘. We show that the two methods do give the same results in S i. Both methods also correctly predict a large destructive interference in the 3s23p4 P30-3s3p5 P31∘ oscillator strength, whereas McGuire’s alternative calculation gives an oscillator strength that is 500 times larger than the experimental value.