Nuclear magnetic octupole moments of and determined from hyperfine-structure calculations
Phys. Rev. A 114, 042801 – Published 1 October, 2026
DOI: https://doi.org/10.1103/pp9b-9wrp
Abstract
We calculate the hyperfine-structure properties of the low-lying states in and using the relativistic coupled-cluster method at the singles and doubles level. The properties include the first-order hyperfine constants and the second-order corrections arising from off-diagonal hyperfine interactions. Based on our theoretical results, we reanalyze the previous hyperfine-splitting measurements of the state in [Daly and Holloway, Phys. Rev. 96, 539 (1954)] and refine the nuclear magnetic octupole moments of these two isotopes. The refined values and are about 13% and 12% larger than the earlier results reported by Daly and Holloway. By providing an independent ab initio determination, the present results offer a reliable set of reference values for the magnetic octupole moments of , which will benefit both future high-precision measurements and nuclear-structure calculations.