ASSIGNMENT OF THE $3p^{2}F_{2} - 3s^{2}A_{1}$ ELECTRONIC TRANSITION OF $ND_{4}$

Abstract

The $14820 cm^{-1}$ Sch""{u}ler band of $ND_{4}$ has been observed in $emission^{1-3}$ and $absorption^{4,5}$. The structure of the recent high-resolution absorption spectrum of this band obtained in a flash discharge $experiment^{5}$ is shown to be fully accounted for as the 0-0 band of the transition $3p^{2}F_{2} - 3s^{2}A_{1}$. The lifetime of the $3s^{2}A_{1}$ ground state is consistent with neutralized ion beam $experiment^{6}$. The $3p^{2}F_{2}$ upper state shows significant spin-orbit coupling $(G_{3/2} - E_{5/2} = 9.155 cm^{-1})$ and Jahn-Teller rotational $effects^{7}$. The theory of the structure of the 1-0, 0-1, and 1-1 bands in the degenerate vibrations will also be discussed.