Chemical Physics Letters 265 (1997) 490-496
(LS) versus (jj) coupling in P 2p inner-shell excited states of PF3
N. Kosugia, R.G. Cavell b, A.P. Hitchcockc
aInstitute for Molecular Science, Okazaki 444, Japan
bChemistry, University of Alberta, Edmonton, Alb., Canada T6G 2G2
cChemistry, McMaster University, Hamilton, Ont., Canada L8S 4MI
Received 14 October 1996; in final form 5 December 1996

The P 2p total and parent ion yield spectra of PF3 have been measured and interpreted with ab initio SCF-CI calculations. The PF3+ yield has only one line at 136.5 eV, without a spin-orbit partner. The ab initio calculations attribute it to the (e -', e)1 A1 state. They predict the (e - 1, e) 3A1 -(e -', e) 'A, state separation is 2.4 eV, much greater than for other P 2p states (0.05-0.5 eV), and much larger than the P 2p - 1 spin-orbit splitting (0.9 eV). We conclude the 136.5 eV state is the (LS) coupled (e - 1, e) 'A , state, and the normally dominant P 2p - 1 spin-orbit (jj) splitting can be ignored. The importance of treating core-valence exchange as well as spin-orbit interactions is discussed.