The hyperfine structures of five lines in the optical spectra of Hg195, Hg195m, and Hg194 have been investigated under high resolution. The nuclear moments, calculated from ratios of hyperfine splittings, are µ(195m)=-1.060±0.01 nm, Q(195m)=1.5±1 b, and µ(195)=+0.526±0.005 nm. Isotope shifts measured relative to Hg196 were found to be Δ(195-196)=+77.2±5 mK,Δ(195m-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)