Laser-induced fluorescence of the A²π_u-X²π_g transition of CS₂⁺ in solid Ne. Reanalysis of vibronic spectra

Dispersed fluorescence spectra in the spectral range 475-575 nm and fluorescence excitation spectra in the range 410-480 nm were recorded for the A²π_u-X²π_g system of CS₂⁺ and its ¹³C- and ³⁴S-isotopic species. Based on a comparison of the relative extents of ¹³C- and ³⁴S-isotopic shifts, new assignments for Fermi polyads of the X²π_g state were derived; they are consistent with recent variational Renner-Teller calculations by Brommer and Rosmus based on three-dimensional potential energy functions derived from ab initio calculations. According to an analogous argument, the vibronic levels of the A²π_u state are assigned based on observed ¹³C- and ³⁴S-isotopic shifts.