The 583.2 GHz torsional hot-band of (D2O)(3)

We report the observation of a new c-type band of (D2O)(3) at 583.215 92(37 ) GHz, which we assign to the k=+/-2(0)<-- +/-1(0) torsional hot-band. The new data includes the first observation of K=0 states for the k=+1(0) and k =-2(0) levels and effects a correct assignment of these states. A new pertu rbation was observed for the K=2 states of the k=+2(0)<-- -1(0) subband spl itting each transition into two equally spaced equal intensity doublets. An alysis of the band and inclusion into a global fit of all torsional bands p roduces negligible differences with previous analyses, and confirms the val idity of the Hamiltonian developed to treat the coupling between torsional motion and overall rotation. The 583.2 GHz band completes the precise chara cterization of all (D2O)(3) vibrational levels below 100 cm(-1). (C) 2001 A merican Institute of Physics.