Remarks on the Determination of Electric Dipole Moments from Rotational Magnetic Moments. The Dipole Moment of Hydrogen Fluoride

The determination of electric dipole moments from isotopic variations of the rotational magnetic moment is considered. It is pointed out that appreciable errors in the dipole moment can result if one neglects the effects of vibrational motion on the high-frequency part of the magnetic susceptibility. Thus, a current discrepancy in the dipole moment of HF determined from the rotational magnetic moments of HF and DF and by the molecular beam electric resonance method is resolved by such vibrational corrections. When these vibrational corrections are made, the dipole moment of HF as determined from the rotational magnetic moments of HF and DF is 1.83±0.05 D (H+F—) instead of 1.65 D, and is in good agreement with the value of 1.818±0.008 D obtained by electric resonance.