https://www.nist.gov/publications/vibrational-spectra-molecular-ions-isolated-solid-neon-xv-infrared-spectroscopic-1
When a Ne:HF mixture is subjected to Penning ionization and/or photoionization by neon atoms in their first excited states, between 16.6 eV and 16.85 eV, and th
molecular ionsspectraisolatedsolidneon