ExoMol Line List XXI: Nitric Oxide (NO)

The line lists are constructed using empirical energy levels (and line positions) and high-level ab inito intensities. The energy levels were obtained using a combination of two approaches, from an effective Hamiltonian and from solving the rovibronic Schroedinger equation variationally.

The effective hamiltonian model was obtained through a fit to the experimental line positions of NO available in the literature for all six isotopologues using the programs SPFIT and SPCAT. The variational model was built through a least squares fit of the ab inito potential and spin-orbit curves to the experimentally derived energies and experimental line positions of the main isotopologue only using the Duo program. The ab inito potential energy, spin-orbit and dipole moment curves (PEC, SOC and DMC) are computed using high-level ab inito methods and the MARVEL method is used to obtain energies of NO from experimental transition frequencies.