Spectroscopic parameters of phosphine, PH3, in its ground vibrational state

TL;DR

This paper reanalyzes the ground state rotational spectrum of phosphine (PH3) using recent high-precision data, leading to improved spectroscopic parameters and insights into hyperfine interactions.

Contribution

It provides a comprehensive reanalysis of PH3's spectrum, incorporating new data and hyperfine effects, resulting in more accurate spectroscopic parameters.

Findings

Improved spectroscopic parameters for PH3

Significant hyperfine interaction effects identified

Enhanced understanding of A1/A2 level splitting

Abstract

The ground state rotational spectrum of PH3 has been reanalyzed taking into account recently published very accurate data from sub-Doppler and conventional absorption spectroscopy measurements as well as previous data from the radio-frequency to the far-infrared regions. These data include Delta(J) = Delta(K) = 0 transitions between A1 and A2 levels, Delta(J) = 0, Delta(K) = 3 transitions as well as regular Delta(J) = 1, Delta(K) = 0 rotational transitions. Hyperfine splitting caused by the 31P and 1H nuclei has been considered, and the treatment of the A1/A2 splitting has been discussed briefly. Improved spectroscopic parameters have been obtained. Interestingly, the most pronounced effects occured for the hyperfine parameters.