(LS) VERSUS (JJ) COUPLING IN P-2P INNER-SHELL EXCITED-STATES OF PF3

The P 2p total and parent ion yield spectra of PF, have been measured and interpreted with ab initio SCF-CI calculations. The PF: yield has only one line at 136.5 eV, without a spin-orbit partner. The ab initio calculations attribute it to the (e(-1),e)(1)A(1) state. They predict the (e(-1),e)(3)A(1)-(e(-1),e)(1)A(1) state separation is 2.4 eV, muc h greater than for other P 2p states (0.05-0.5 eV), and much larger th an the P 2p(-1) spin-orbit splitting (0.9 eV). We conclude the 136.5 e V state is the (LS) coupled (e-l,e) 1A, state, and the normally domina nt P 2p(-1) spin-orbit(ii) splitting can be ignored. The importance of treating core-valence exchange as well as spin-orbit interactions is discussed.