Abstract
We have recorded the (0,0) and (0,0) bands of gold monosulphide (AuS) at sub-Doppler resolution by intermodulated fluorescence spectroscopy. These two red-degraded bands lie at 642.3 and 613.8 nm, respectively. The high resolution of the experiment enabled the accurate determination of the rotational, fine and 197Au hyperfine constants of the two excited states for the first time. The Fermi contact dipolar and electric quadrupolar interactions in the upper states can be understood in terms of the electronic configurations from which they arise. The signs of the spin–rotation parameters, γ(A2Σ+) = −0.080821(24) cm−1 and γ(B2Σ−) = 0.136427(20) cm−1, suggest that the fine structures of these states arise primarily by interactions with inverted 2Π states lying at higher energy.
GRAPHICAL ABSTRACT
Acknowledgment
The authors are grateful to Timothy C. Steimle (Arizona State Univ.) for helpful discussions.
Disclosure statement
No potential conflict of interest was reported by the authors.