Quadrupole Coupling in the Hyperfine Structure of the Spectrum of La I

Abstract

According to the theory of Sternheimer, it can be written Q=(1+Δ)Q′, in which Q is the true quadrupole moment and Q′ is the apparent quadrupole moment obtained by spectroscopic means neglecting the shielding effect; Δ is the so-called shielding correction or core correction. The author obtained in a previous work Δ=−0.6 for 5d²6s⁴F_3⁄2 of La I. In the present work Δ=−0.6 and −0.7 were obtained for 5d²6s⁴F_9⁄2 and ⁴F_7⁄2 respectively of La I. They agree with the value for ⁴F_3⁄2 within experimental error.