Nuclear Quadrupole Moments of Bismuth

Abstract

Multiconfiguration Dirac-Fock models have been employed to compute the electric field gradient in the ground state of the neutral bismuth atom. Combined with the experimental electric quadrupole hyperfine interaction constant, one obtains for ${}^{209}\mathrm{Bi}$ the nuclear quadrupole moment $Q\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}516(15)\mathrm{mb}$, which is almost $40%$ away from the previously accepted standard value [ $\ensuremath{-}370(26)\mathrm{mb}$], and narrows by over an order of magnitude the long-standing, extremely broad array of various results ranging from $\ensuremath{-}370$ to $\ensuremath{-}710\mathrm{mb}$. The recent $Q$ values of ${}^{{202\ensuremath{-}208,210}^{m}\ensuremath{-}213}\mathrm{Bi}$ by Pearson et al. suffer a consequent change.