The H₂¹⁶O molecule: line position and line intensity analyses up to the second triad

Abstract

Accurate line strengths were obtained for the H₂¹⁶O molecule in the 800–1750 cm⁻¹ region. Measurements were carried out for 974 lines including pure rotational transitions and ν2, 2ν₂ −ν₂, 3ν₂ −2ν₂, and ν₁ −ν₂ band transitions. The absolute experimental uncertainty on the measurements, in percent of the observed line strength, is 1.5% or better for a number of lines. Line position and line intensity analyses of data pertaining to water and involving the eight first vibrational states of this molecule were also carried out. The data considered in the line position analysis were taken from the literature and involved rotational energy levels, line positions, and microwave frequencies. The data considered in the line intensity analysis involve the line strengths measured in this work, line strengths available from the literature, and Stark coefficients. The theoretical model used in both analyses accounts for anomalous centrifugal distortion effects. The unitless standard deviation achieved in both analyses is 1.2.