Hyperfine Structure ofN15H3

Abstract

Hyperfine structure of the inversion transition for the $J-K=4-4, 5-5, 6-6, \mathrm{and} 7-7$ rotational states of ${\mathrm{N}}^{15}$ ${\mathrm{H}}_3$ was measured with a two-cavity maser spectrometer. Previous data on the $J-K=2-2\mathrm{}$ state and these new data are analyzed including the nitrogen ${\overrightarrow{\mathrm{I}}}_N·\overrightarrow{\mathrm{J}}$ term, the hydrogen $\overrightarrow{\mathrm{I}}·\overrightarrow{\mathrm{J}}$ term, the hydrogen-nitrogen spin-spin interaction, the hydrogen-hydrogen spin-spin interaction, and a scalar electron-coupled spin-spin interaction. For the $J-K=2-2, 4-4, 5-5, \mathrm{and} 7-7$ states a consistent set of coupling strengths are found such that the calculated frequencies agree with the data to within the experimental accuracy. There are still large discrepancies between calculated and experimental frequencies for the $J-K=1-1, 3-3, \mathrm{and} 6-6$ states.