Knowledge Bank

Reassignments are presented for the hyperfine patterns of six $\mathrm{<mrow\; data-mjx-texclass="ORD">15</mrow>}NH3$ inversion doublets. The new assignments lead to different hyperfine parameters than previously reported. Previous disagreement between theory and experiment for the J=3, K=2 hyperfine pattern in the $\mathrm{<mrow\; data-mjx-texclass="ORD">14</mrow>}NH3$ inversion doublet spectrum is removed by including the effect of centrifugal distortion on the quadrupole splitting. The nature, i.e. theoretical or experimental, of discrepancies in the fit of the J=K=6 hyperfine pattern for $\mathrm{<mrow\; data-mjx-texclass="ORD">15</mrow>}NH3$ could not be established with certainty.