Molecular beam electric resonance study of the molecular Zeeman spectrum of lithium chloride

Abstract

A high resolution study of the molecular Zeeman spectrum of lithium chloride in the first rotational state (J = 1) and various isotopic and vibrational (ν) states has been performed using a molecular beam electric resonance apparatus which includes an external electromagnet for the resonance region. By fitting the observed resonance lines to an appropriate molecular Hamiltonian, the values of the rotational magnetic moment (gJ), the nuclear shielding anisotropies for chlorine (σTCl) and lithium (σTLi), and the molecular magnetic susceptibility anisotropy (ξT) were determined for each state. The values of these constants obtained are as follows (numbers in parentheses are the uncertainties in the final figures): Molecule (state)gJ (nuclear magnetons)σTCl (ppm)σTLi (ppm)ξT (10−30erg/G2)Li7Cl35 (J = 1, ν = 0):+ 0.100419(31)− 184(27)− 36(14)+ 2.52(25)Li7Cl35 (J = 1, ν = 1):+ 0.100642(80)− 301(83)− 42(52)+ 2.04(27)Li7Cl37 (J = 1, ν = 0):+ 0.101336(40)− 253(100)− 74(37)+ 3.13(30) The resonances were obtained in the low electric field limit by making explicit use of the motional electric field experienced by the molecules in the magnetic field of the resonance region. The motional field Stark shift is also used to calibrate the velocity selection properties of the quadrupole state selectors.