Abstract

Vacuum ultraviolet (VUV) spectra of Cl₂ are highly irregular due to extensive excited state perturbations, and in the past, have been difficult to interpret¹. This situation was offset substantially by the ab initio calculations of Peyerimhoff and Beunker². They showed that the strongest VUV transition below 145 nm involves a third tier ${}^1{\displaystyle {\sum }_u^{+}}$ ion-pair valence state dissociating to Cl⁺(¹D_g) + Cl^-(¹S_g), which interacts with the near isoenergetic 4pπ ${}^1{\displaystyle {\sum }_u^{+}}$ Rydberg state leading to the formation of a double well potential curve, labelled 1 ${}^1{\displaystyle {\sum }_u^{+}}$.

© 1995 Optical Society of America