High-resolution Fourier-transform spectroscopy of 18O-enriched water molecule in the 1080–7800 cm −1 region

Abstract

Fourier-transform absorption spectrum of 18O enriched water sample was recorded in the 1080–7800 cm −1 region. The transitions of H 2 18O were assigned on the base of the high accuracy ab initio calculations by Partridge and Schwenke (PS). One thousand two hundred and forty-six ro-vibrational energy levels were retrieved, which belong to the v 1 + 1 2 v 2 + v 3 = 0.5 , 1, and 1.5 polyads: (0 1 0), (1 0 0), (0 2 0), (0 0 1), (1 1 0), (0 1 1), and (0 3 0) states. Four hundred and thirty-two of them are reported for the first time. The results are also investigated comparing with the PS calculations and the available literature data in the considered spectral range. HD 18O as a small concentration in the sample, more than 4900 transitions were also observed. These transitions yield 1066 ro-vibrational energies of nine vibrational states, 504 energy levels were obtained for the first time.