Calculation of the Magnetic Hyperfine Structure of theD1,D3,F1, andF3States ofLi+7

Abstract

The separations of the magnetic-hyperfine-structure levels of the ${}_{}{}^1{}_{}{}^{}D$, ${}_{}{}^3{}_{}{}^{}D$, ${}_{}{}^1{}_{}{}^{}F$, and ${}_{}{}^3{}_{}{}^{}F$ states of the ion ${}_{}{}^7{}_{}{}^{}\mathrm{Li}_{}^{+}{}_{}{}^{}$ have been calculated taking into account the mixing of singlet and triplet functions which arises from each configuration ($1snd$) and ($1snf$) by the spin-orbit and spin-spin interactions of Breit's Hamiltonian and the magnetic interaction between the nucleus and the $1s$ electron (Fermi-contact term). The electronic wave functions used are linear combinations of Slater determinants built on hydrogenic orbitals. The calculated distribution of levels is in agreement with experimental results and confirms the coupling rules introduced by Herzberg and Moore for the interpretation of the spectra. The calculations predict an apparent hyperfine structure of the singlet states of ${}_{}{}^7{}_{}{}^{}\mathrm{Li}_{}^{+}{}_{}{}^{}$ which is analogous to that observed in the $n{}_{}{}^1{}_{}{}^{}D$ states of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$.