Knowledge Bank

The $d3\Pi g-c3\Sigma u+$ system of dicarbon was observed in a discharged supersonic jet of C$2$H$2$.}, \textit{J. Chem. Phys.} \underline{\textbf{125}}, 231101 (2006).} A spectral survey was carried out based on the result of high-level \textit{ab initio} calculation.}, \textit{J. Chem. Phys.} \underline{\textbf{126}}, 084302 (2007).} LIF excitation spectra of the band system were recorded by detecting fluorescence of the Swan system ($d3\Pi g-a3\Pi u$). Several molecular constants of the $c3\Sigma u+$ state were experimentally determined from the rotationally resolved spectra. Characterization of the $c3\Sigma u+$ state of C$2$ is of importance to astrophysical models of the species.