Journal of Chemical Physics, Vol.115, No.11, 5126-5131, 2001
The 4p pi(3)Pi(g)-a(3)Sigma(+)(u) system in Ne-20(2) and Ne-22(2)
Excitation spectra for the 4p pi (3)Pi (g)-a (3)Sigma (u)+ system in Ne-20(2) and Ne-22(2) have been used to characterize the v=0 through v=3 levels in both electronic states. This is the first time levels with v >1 have been characterized experimentally in either dimer. Rotational analyses lead to B-e- and alpha (e)-values of 0.5638 cm(-1) and -0.9000x10(-2) cm(-1) and of 0.5113 cm(-1) and -0.6651x10(-2) cm(-1) for the a (3)Sigma (u)+ states in Ne-20(2) and Ne-22(2), respectively. The B-e- and alpha (e)-values are, respectively, 0.5716 cm(-1) and -0.6429x10(-2) cm(-1) (Ne-20(2)) and 0.5201 cm(-1) and -0.4172x10(-2) cm(-1) (Ne-22(2)) for the 4p pi (3)Pi (g) state. The vibrational parameters omega (e), x omega (e) are found to be 556.2, 10.2 cm(-1), and 593.2, 7.5 cm(-1) for the a (3)Sigma (u)+ state and 4p pi (3)Pi (g) state, respectively, in Ne-20(2) with corresponding values of 529.5, 9.75 cm(-1), and 567, 7.5 cm(-1) in Ne-22(2). The observed vibrational level differences [DeltaG((v+1/2))-values] for the 4p pi (3)Pi (g) state are within 0.5% of analogous spacings for the ground electronic state (X (2)Sigma (u)+) of Ne-2+ reported by Kim [Phys. Rev. Lett. 68, 1311 (1992)]. <(C)> 2001 American Institute of Physics.