Journal of Chemical Physics, Vol.107, No.19, 7690-7694, 1997
On the origin of the heavy atom effect in the fine-structure splitting of the 1 (2)Pi state of alkali metal P-2-rare gas van der Waals molecules
The fine-structure splitting of the (1 (2) Pi(Omega), nu) levels in Li(1s (2)2p, P-2)Ar and Li(1s (2)2p, P-2)Ne is determined. Analysis of the electronic wave functions demonstrates that the heavy atom contribution to the fine-structure splitting results from the antibonding mixture of valence p(pi) orbitals on the rare gas and metal atoms. Rydberg orbitals do not contribute significantly to the heavy atom effect. (C) 1997 American Institute of Physics.