Resonance calculations of d − f intervals for the lithium Rydberg states

Abstract

By using the energies of the 1s2nd (n=3–5) and 1s2nf (n=4–6) states for a lithium atom, calculated with the full core plus correlation method, quantum defect functions are obtained which vary smoothly with energy based on quantum defect theory. Then these functions are separately used to construct a system equation to calculate the energies and quantum defects of the 1s2nd and 1s2nf (n=7–11) states for the lithium atom. Separations between the centres of gravity of the nd and nf levels (n=7–11) are also predicted and compared with the experimental and theoretical data available in the literature.