Microwave spectra of D 217O and D 218O

Abstract

Forty lines of the microwave spectra of D 2 17O and D 2 18O have been measured in the region from 8 to 400 GHz and analyzed according to Watson's centrifugal distortion theory. Comparison of the results obtained for D 2 16O, D 2 17O, and D 2 18O demonstrates their internal consistency. The transferability of the parameters according to the isotopic substitution rules is evidence for the validity of the model chosen for the study of the ground state of heavy water. The effective rotational constants deduced from the observed spectra are very close to the values calculated using Oka's second order theory. The values obtained in MHz are: A = 456766.9, B = 218041.0, C = 144701.5 (D 2 17O;) A = 451891.9, B = 218045.2, C = 144201.7 (D 2 18O;). The hyperfine structure of the D 2 17O lines has been analyzed using as a reference the corresponding quadrupole coupling tensor of HD 17O with the appropriate rotation. The values of χ gg in MHz used for the analysis are: x χχ = - 1.2104, x yy = 10.1068, x zz = - 8.8964.