Reinterpretation of Molecular Beam Hyperfine Data for 14NH3 and 15NH3

Abstract

Reassignments are presented for the hyperfine patterns of six 15NH3 inversion doublets. The new assignments alter the sign of the nitrogen-hydrogen spin-spin interaction constant. Previous disagreement between theory and experiment for the hyperfine pattern of the J = 3, K = 2 14NH3 inversion doublet is removed by including the effect of centrifugal distortion on the quadrupole splitting. An explanation is presented for a discrepancy remaining in the fit of the J = K = 6 hyperfine pattern of 15NH3.