High-resolution study of the first hexad of D2O

The high-resolution Fourier transform spectra of the D2O molecule have been recorded and assigned in the 4200-5700 cm region where the vibration-rotation bands 2 upsilon(1), 2 upsilon(3), upsilon(1), + upsilon(3), upsilon(1) + 2 upsilon(1), 2 upsilon(2) + upsilon(3), and 4 upsilon(2) are located. The presence of numerous and very strong accidental perturbations between the states of the hexad makes it necessary to take into account not only ordinary resonance interactions of the Fermi, Darling-Dennison, and/or Coriolis types, but interactions between the states (upsilon(1)upsilon(2)upsilon(3)) and (upsilon(1) -/+ 2 upsilon(2) +/- 2 upsilon(3) +/- 1) as well. Parameters of all six vibrational states of the hexad were obtained from the fit of experimental energy values. (C) 2000 Academic Press.