D216O: ICLAS between 13 600 and 14 020 cm−1 and normal mode labeling of the vibrational states

摘要: Abstract The high resolution absorption spectrum of dideuterated water, D 2 16 O, has been recorded by Intracavity Laser Absorption Spectroscopy (ICLAS) in the 13 600–14 020 cm −1 spectral region which is highest energy reported so far for this water isotopologue. Because HD O stronger three orders magnitude under study, it was necessary to use deuterium enrichment order minimize lines overlapping spectrum. With sensitivity achieved (noise equivalent α min ∼10 −9  cm ), transitions with line strengths on 5 × 10 −28 molecule could be detected. analysis, based recent variational calculations provided a set 177 new rovibrational levels belonging six vibrational states. most complete 53 including newly determined band origins, constructed from an exhaustive review literature data. fitting parameters effective Hamiltonian allowed reproduce whole energies rms deviation 0.055 cm . This simple model gave consistent labels states up 18 000 cm Above 15 000 cm , Fermi and Darling-Dennison resonance interaction were found induce strong mixings wave functions normal mode basis, leading ambiguous labeling.