Equilibrium binding energies (eV), equilibrium positions (Å) and quantum defects for Rydberg states converging on A 2Πu
Table 8. Equilibrium binding energies (eV), equilibrium positions (Å) and quantum defects for Rydberg states converging on A 2Πu. The quantum defect is given relative to the A2Πu state of N_2^+, the term in the parentheses gives the Rydberg electron symmetry. States given with full spectroscopic notation have been characterized previously and appear also in table 2.
Potential energy curves for electronically excited states of molecular nitrogen are calculated using three different ab initio procedures. The most comprehensive of these involves the use of scattering calculations, performed at negative energy using the UK molecular R-matrix method. Such calculations are used to characterize all the Rydberg states of N2 with n ≤ 6 and ℓ ≤ 4 as well as many higher states including some Rydberg states associated with the first excited A 2Πu state of N_2^+. Many of these states are previously unknown. The calculations are performed at a dense grid of internuclear separations allowing the many avoided crossings present in the system to be mapped out in detail. Extensive comparisons are made with the previously available data for excited states of N2.