nuclear theory value by an order of magnitude [@DanFerGeb74]. In principle, one could extract $\Pi$ from the measurements made by Singh *et al.* in neutral $^{173}\mathrm{Yb}$ [@Singh], but its contribution was neglected in that work. Here, in order to leverage the considerable experimental toolbox built around $\mathrm{Yb}^+$ for quantum information applications, we evaluate the necessary electronic structure factors for $^{173}$Yb$^{+}$ needed to enable extraction of the hexadecapole moment of this isotope from future spectroscopic measurements.

The $\mathrm{Yb}^{+}$ ground state hyperfine structure is among the most precisely measured and easiest to control of all the HFS in atomic physics owing to its $m_F=0$ “clock states” and its readily available state preparation and readout schemes. The ${}^2S_{1/2}$ HFS of ${}^{171}\mathrm{Yb}^+$ has been used for decades for frequency standards and quantum information processors, and its splitting has been known to $\mathrm{mHz}$ precision for many years [@Fisk1997]. The long coherence time of clock-state qubits defined on this hyperfine splitting (recently shown to exceed 10 minutes [@Wang2017]) has made ${}^{171}\mathrm{Yb}^{+}$ a premier qubit host for quantum computing and quantum simulation [@Olmschenk2007; @Figgatt2019; @Zhang2017; @Landsman2019; @Wright2019]. Likewise, the metastable $^2F_{7/2}^o$ electronic state of ${}^{171}\mathrm{Yb}^+$ lives for years, and the E3 transition on ${}^2S_{1/2} \! \leftrightarrow {}^2F_{7/2}^o$ 