Experimental Energy Levels of the Water Molecule

Experimentally derived energy levels are presented for 12248 vibration–rotation states of the $H216O$ isotopomer of water, more than doubling the number in previous, disparate, compilations. For each level an error and reference to source data is given. The levels have been checked using energy levels derived from sophisticated variational calculations. These levels span 107 vibrational states including members of all polyads up to and including 8ν. Band origins, in some cases estimates, are presented for 101 vibrational modes.