Vibrational distributions in N 2 with an improved calculation of energy levels using the RKR method

Abstract

The potential curve of the N 2 ground state ( X 1 Σ g + ) has been accurately reconstructed using the Rydberg–Klein–Rees (RKR) method extrapolated by a Hulburt and Hirschfelder potential for longer internuclear distances. Solving the corresponding radial Schrödinger equation yields 60 bound levels above v = 0, whose energies may be fitted by the following polynomial expansion: G ( v ) = ∑ i = 1 5 a i ( v + 1 / 2 ) i , with the coefficients a i in cm −1 equal to 2378.1, −18.516, 0.26662, −6.2127 × 10 −3, and 3.4215 × 10 −5, respectively, for i = 1–5. The effects of considering this more accurate potential on the vibrational distribution function of N 2(X, v) molecules obtained in nitrogen microwave discharges and post-discharges are compared with previous calculations, using a smaller vibrational manifold.