Calculations of Rydberg energy levels for Ni XVIII using the weakest bound electron potential model theory

摘要

Martin expression about the quantum defect of single-valence atoms is extended to many-valence atoms by identifying the weakest bound electron (WBE) under the weakest bound electron potential model (WBEPM) theory. Six Rydberg series energy levels of 2p~6np~2P°_(1/2) (n ≥ 3), 2p~6np~2P°_(3/2) (n ≥ 3), 2p~6nd~2D_(3/2) (n ≥ 3), 2p~6nd~2D_(5/2) (n ≥ 3), 2p~6nf~2F°_(5/2) (n ≥ 4), and 2p~6nf~2F°_(7/2) (n ≥ 4) for Ni XVIII are calculated by this method. The calculated results are in good agreement with the experimental results.