Evidence for a nuclear hexadecapole interaction in the hyperfine spectrum of LiI (original) (raw)

The molecular beam electric resonance technique has been used to examine the hyperfine spectrum of 7 LiI to determine the nuclear hexadecapole interaction of the iodine nucleus. The nuclear magnetic octupole interaction was also considered but found to be marginally significant. A total of 172 transitions in vibrational states 0-3 and rotational states 1-6 have been included in a fit to determine the iodine nuclear quadrupole, spin-rotation, and hexadecapole interactions, the lithium quadrupole and spin-rotation interactions, and the tensor and scalar parts of the spin-spin interaction. Vibration and rotation dependencies of these constants have been determined. The results include: eHhϭϪ0.0151(30), eQ I q I ϭϪ194351.212(17)Ϫ8279.521(46)(vϩ1/2) ϩ100.616(34)(vϩ1/2) 2 Ϫ0.3949(73)(vϩ1/2) 3 Ϫ6.41977(50)J(Jϩ1)ϩ0.10593(33)(vϩ1/2)J(J ϩ1), eQ Li q Li ϭ172.613(52)Ϫ3.26(14)(vϩ1/2)ϩ0.00145(87)J(Jϩ1), c I ϭ6.80260(32) ϩ0.00303(49)(vϩ1/2)Ϫ0.000118(13)J(Jϩ1), c Li ϭ0.75872(72)Ϫ0.0088(11)(vϩ1/2), c 3 ϭ0.62834(68)Ϫ0.0050(11)(vϩ1/2), c 4 ϭ0.06223(36)ϩ0.00041(26)(vϩ1/2), and e⍀ I I Ј ϭ0.000112 , all in kHz with one standard deviation uncertainties for the last 2 digits in ͑ ͒.