Term energies of 1s2nf high Rydberg states for the lithium atom

Abstract

Ionization potentials and quantum defects of 1s2nf bound states and their adjacent continuum states for the lithium atom are calculated with the R-matrix theory; then the quantum defect function (QDF) of the 1s2nf channel is obtained, which varies smoothly with the energy based on the quantum defect theory. The original QDF is calibrated from a more accurate literature value and used to calculate quantum defects, ionization potentials and term energies (relative to the 1s22s ground state) of 1s2nf high Rydberg states of the lithium atom. The term energies in this work are, on the whole, in good agreement with the experimental data in the literature.