Moleculargvalues, magnetic susceptibilities, molecular quadrupole moment, and spin-rotation interaction in15NH3

The first-order Zeeman effect was observed at 25 kg on the inversion transition in 15NH3 for seven different rotational states. The measured g values are g ┴ = 0·563±0·001 and g ∥ = 0·500±0·001. The upper limit on the magnetic susceptibility anisotropy in ammonia is determined to be The molecular quadrupole moment is Q ∥ = - (1·9±1·0) × 10-26 e.s.u. cm2. The diagonal elements in the diamagnetic and paramagnetic susceptibility tensors are given along with the second moment of the electronic charge distribution. The molecular g values are combined with the nitrogen and hydrogen spin-rotation constants to obtain values of 1/r 3 matrix elements between ground and excited states. The results for NH3 are compared to the recent results in H2O.