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

The most complete set of 53 vibrational energy levels of D216O, including the three newly determined band origins, was constructed from an exhaustive review of the literature data. The fitting of the parameters of the vibrational effective Hamiltonian has allowed to reproduce the whole set of vibrational energies with an rms deviation of 0.055 cm−1. This simple model gave consistent vibrational labels of the D216O states up to 18 000 cm−1. Above 15 000 cm−1, Fermi and Darling-Dennison resonance interaction were found to induce strong vibrational mixings of the wave functions in the normal mode basis, leading to ambiguous vibrational labeling.