Theoretical investigation of near-threshold photoionization of N₂

Photoionization (PI) spectrum of the N₂ molecule is modelled using a first-principles approach combining the multichannel quantum defect theory and electron scattering calculations performed using the UK R-matrix codes.  The PI spectra were determined starting from the ground and several excited vibrational levels of N₂ in the ground electronic state X¹Σ_g⁺. Excited electronic states and vibrational motion of the N₂⁺ ion are accounted for.  The spectrum obtained for the lowest vibrational level of N₂ was compared to available experimental data. Major resonances in the obtained spectrum were characterized using the quantum defect technique.