We discuss the ground states of LnF for all the lanthanides, based on Dirac-Fock-Roothaan (DFR) calculations with average-configuration in the reduced frozen-core approximation. The electron configurations of the ground states are (4f)n-1 (5d)1 (6s)1 for LaF - NdF, (4f) n (6s)1 for PmF and SmF, and (4f)n-1 (6s) 2 for EuF ̃ LuF, in contrast to the (4f)n (6s) 1 configurations of the gaseous cation, Ln+. Although the ground state configuration varies, the bonding character in the ground states is ionic for all LnF; a single electron is transferred from the Ln atom to the F atom. We also discuss the excited states having configurations (4f)n-1 (6s)2, (4f)n-1 (5d)1 (6s)1, and (4f)n (6s)1. The complete active space configuration interaction calculations were performed for GdF, using two kinds of DFR spinor sets, one of which is a nonrelativistic-like spinor set and the other relativistic one. The nonrelativistic-like spinor set gives 8σ -- like (nonrelativistic like) ground state, which is consistent with the experiment.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Physical and Theoretical Chemistry