HYPERFINE SPECTRUM OF NACL BY MOLECULAR-BEAM ELECTRIC RESONANCE

The hyperfine spectrum of NaCl has been observed at very low field using the molecular-beam electric resonance method. The Hamiltonian is expressed in a representation in which the combined quadrupole term is diagonal when the quadrupole interaction constants of the two nuclei are equal. The analysis of the spectrum then gives for the constants X+≡[(eqQ) Na+(eqQ)Cl]/2, X-≡[(eqQ) Na-(eqQ)Cl]/2, c+≡ (c1+c 2)/2, c3, and c4 the values (in kilohertz) for 23Na55Cl: X+=-5658.0±0.1, X -=-16±50, c+= +0.51±0.01, c2= +0.22±0.02, and c4= +0.05±0.03 for v=0; X +=-5716.3±0.5 and X-=+116±20 for v=1; X +=-5772.6±0.7 and X-=+235±12 for v=2; and X+=-5828±1 and X-=+340±15 for v=3. Lines have also been observed corresponding to 33Na35Cl, J=2, and 23Na37Cl, J=1.