Identification of the nd Δ and Σ States and the 1,3Φ←←X  3Σ− g Transition of O2 by Resonant Multiphoton Ionization

Spectra of the 3dRydberg state region of O2 have been obtained by two‐photon resonant ionization of the ground electronic state. By varying the rotational distribution and radiation polarization, all observed bands were identified and attributed to excitation of Σ, Δ, and Φ states. Earlier assignments were corrected. The Δ and Φ assignments are complete while the Σ assignments are so far incomplete