A coupled-channel model of the ³Π_u states of N₂: Structure and interactions of the 3sσ_gF ₃ ³Π_u and 3pπ_uG₃ ³Π_u Rydberg states

New and existing spectroscopic data on N2, obtained using a wide variety of experimental techniques, are interpreted using a coupled-channel Schrödinger-equation (CSE) model of the structure and predissociation dynamics for the interacting Rydberg and valence states of Π3 u symmetry. As a result, v>0 levels of the 3p π u G3 Π3 u Rydberg state are assigned correctly for the first time, leading to the identification of very strong perturbations in the G3 -state vibrational structure. A four-channel CSE model, which includes the 3s g F3 Π3 u and 3p π u G3 Π3 u Rydberg states and the C′ Π3 u and C Π3 u valence states, indicates strong Rydberg-Rydberg coupling between the F3 and G3 states, strong Rydberg-valence coupling between the G3 and C′ states, and weaker coupling between the F3 and C′ states.