Measurements of positions, strengths and self-broadened widths of H 2O from 2900 to 8000 cm −1: line strength analysis of the 2nd triad bands

Abstract

High-resolution spectra of H 2O were recorded with a Fourier-transform spectrometer covering H 2O transitions from 2900 to 8000 cm −1. Over 13,000 absorptions were measured to determine line positions, strengths and self-broadened half-width coefficients. The H 2 16O line strengths of the (0 3 0)–(0 1 0), (1 1 0)–(0 1 0), (0 1 1)–(0 1 0) and (0 3 0)–(0 0 0), (1 1 0)–(0 0 0), (0 1 1)–(0 0 0) bands were fitted to a quantum mechanical model which involves the interactions between the (0 3 0), (1 1 0), and (0 1 1) vibrational states. Also fitted were experimental strengths of the hot bands; (1 2 0)–(0 1 0) and (0 2 1)–(0 1 0). The model includes 14 dipole matrix elements for B- and A-type transitions. The measured line positions were used along with hot water emission measurements (for the (0 3 0), (0 4 0), and (0 5 0) states of H 2 16O) in an analysis to obtain high-accuracy energy level values in the (0 3 0), (1 1 0), (0 1 1), (0 4 0), (1 2 0), (0 2 1), (2 0 0), (1 0 1), (0 0 2), and (0 5 0) vibrational states of H 2 16O and the (1 1 0) and (0 1 1) states of H 2 17O. Also included were measurements and analysis of self-broadened half-widths for over 4700 absorptions between 4405 and 7729 cm −1. The results from this investigation provide new information for the noted H 2 17O bands and present a more accurate representation of the measured H 2 16O bands.