Vibrational levels and statistical analysis of the X(1Σg+) ground state of CS2

Abstract

Single rovibronic levels in the perturbed B21(Δu1) state of CS2 molecules in a cold molecular beam were excited by ultraviolet (UV) photons from a frequency doubled single mode continuous wave (cw) dye laser. The dispersed fluorescence spectrum, detected by a liquid nitrogen (LN) cooled charge coupled device (CCD) array behind a monochromator allowed the determination of vibrational term values in the X(1Σg+) state from the (0,00,0) level up to 20 000 cm−1. Based on calculations including Fermi resonances, most of the measured vibrational bands could be assigned to several vibronic ground state level progressions. A statistical analysis of the positions of all measured levels shows for the nearest neighbor distances and the Δ3 statistics a pure Poissonian distribution. This indicates that no strong correlation between neighboring vibrational levels nor long range interactions are present and therefore no chaotic behavior could be found in contrast to the cases of NO2 and SO2.