Vibrational distributions in N2 with an improved calculation of energy levels using the RKR method

The potential curve of the N2 ground state (X1Σg+) 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=15ai(v+1/2)i, with the coefficients ai 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 N2(X, v) molecules obtained in nitrogen microwave discharges and post-discharges are compared with previous calculations, using a smaller vibrational manifold.