Multiplet Structure and Hyperfine Structure of the Spectrum of Mercury

Analysis of the spectrum of Hg I resulted in locating the level 5 d 9 6 s 2 6 p 1 F 3 in the range 4392–4139 cm -1 measured from the ionization limit or 79792–80045 cm -1 measured from the normal state. The compositions of some levels of the configurations 5 d 9 6 s 2 6 p and 5d 10 6 s 6 p were calculated. The hfs of some lines of the mercury spectrum was measured, using enriched isotope as well as natural mercury. The quadrupole moment of Hg 201 that was deduced from the hfs of 5 d 9 6 s 2 6 p 1 D 2 is 0.43 barn (1 barn=10 -24 cm 2 ), the shielding correction being neglected. If the correction is introduced, this becomes somewhat smaller, but is still in reasonable agreement with the value 0.4 2 barn that was published previously by the author. The agreement seems to indicate that the wave functions for the configuration 5 d 9 6 s 2 6 p given in the present work are accurate enough for calculating the quadrupole moment. It is concluded that Q (Hg 201 )=0.4 2 barn, the shielding correction being included.