Frequency Measurement of Pure Rotational Transitions of D(2)O from 0.5 to 5 THz.

Frequencies of pure rotational transitions of D(2)O were measured in the region 0.5-5 THz with a high-precision far-infrared spectrometer using a tunable radiation source. Measured frequencies of about 150 spectral lines, 30 of them being newly measured lines, provide an excellent frequency standard for the far-infrared region together with our previous measurements on H(2)(16)O, H(2)(17)O, and H(2)(18)O. Molecular parameters of Watson's A-reduced Hamiltonian have been obtained to reproduce the observed frequencies. Copyright 2001 Academic Press.