The hyperfine structures of five lines in the optical spectra of Hg<sup>195</sup>, Hg<sup>195<i>m</i></sup>, and Hg<sup>194</sup> have been investigated under high resolution. The nuclear moments, calculated from ratios of hyperfine splittings, are µ(195<sup><i>m</i></sup>)=-1.060±0.01 nm, <i>Q</i>(195<sup><i>m</i></sup>)=1.5±1 b, and µ(195)=+0.526±0.005 nm. Isotope shifts measured relative to Hg<sup>196</sup> were found to be Δ(195-196)=+77.2±5 mK,Δ(195<sup><i>m</i></sup>-196)=+92.6±5 mK,and Δ(194-196)=+143±10 mK. The last result is not in agreement with published measurements. Further investigation is required before a theory can be considered applicable.
HERBERT KLEIMAN and SUMNER P. DAVIS, "Hyperfine Structures, Isotope Shifts, and Nuclear Moments of Hg195, Hg195m, and Hg194," J. Opt. Soc. Am. 53, 822-827 (1963)