Energy level structure and potential energy curve of the state of Ne2 by high-resolution VUV laser spectroscopy

The C 0 u + state of Ne2 has been investigated by high-resolution vacuum ultraviolet laser spectroscopy. Rotationally resolved spectra of the C 0 u + ( v ′ = 0 - 12 ) ← X 0 g + ( v ″ = 0 ) transitions have been recorded for the isotopomers 20Ne2, 20Ne–22Ne and 20Ne–21Ne and used to extract the potential energy curve of the C 0 u + state in a nonlinear, least-squares fitting procedure. The resulting curve possesses the correct long-range behaviour and two minima at internuclear distances of 2.95 and 4.09 Å located −167.7 and −77.5 cm−1 below the Ne(1S0) + Ne∗(3s′[1/2](J = 1)) dissociation limit, respectively. The C 0 u + state is found to be predissociative and fragments to Ne(1S0) + Ne∗(3s[3/2](J = 1)).