Abstract
The hyperfine structure of the rotation-inversion (nu(2) = 0(+), 0(-), 1(+), 1(-)) states of the (NH3)-N-14 and (NH3)-N-15 ammonia isotopomers is rationalized in terms of effective (ro-inversional) hyperfine-structure (hfs) functions. These are determined by fitting to available experimental data using the Hougen's effective hyperfine-structure Hamiltonian within the framework of the non-rigid inverter theory.
Involving only a moderate number of mass independent fitting parameters, the fitted hfs functions provide a fairly close reproduction of a large majority of available experimental data, thus evidencing adequacy of these functions for reliable prediction. In future experiments, this may help us derive spectroscopic constants of observed inversion and rotation-inversion transitions deperturbed from hyperfine effects.
The deperturbed band centers of ammonia come to the forefront of fundamental physics especially as the probes of a variable proton-to-electron mass ratio.