15min:

S. YU, J. C. PEARSON, B. J. DROUIN, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA; H. S. P. MÜLLER, S. BRÜNKEN, I. Physikalisches Institut, Universität zu Köln, 50937 Köln, Germany; M. A. MARTIN-DRUMEL, O. PIRALI, D. BALCON, M. VERVLOET, Ligne AILES -- Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin, 91192 Gif-sur-Yvette, France; AND L. H. COUDERT, LISA, CNRS/Universités Paris Est et Paris Diderot, 61 Avenue du Général de Gaulle, 94010 Créteil, France.

Although water is just a simple triatomic molecule, its spectroscopy still remains a challenge due to the ever increasing amount of available data. Two types of data have been recently obtained for water: \beginitemize em Accurate frequencies have been measured for transitions in the sub millimeter and terahertz domains involving high-lying rovibrational levels up to the first triad. 149 transitions have been measured between 300~GHz and 2~THz and 26 from 2.5 to 2.7~THz. These b-type transitions take place within one of the five first vibrational states.

em Far infrared transitions involving high-lying rovibrational levels have been recorded recently in the 50 to 600~cm^-1 region using the emission spectrum of a continuous flow of water vapor rovibrationaly excited by an electrodless radio-frequency discharge. 3793 transitions with K_a = 1 within one of the five first vibrational states of the molecule have been assigned so far and involve J-values up to 25 and K_a-values up to 15. There remains a large number of unassigned transitions involving either higher lying vibrational states, larger values of K_a, or taking place between different vibrational states. \enditemize The paper will focus on the results of the analysis of a large data set consisting of already published data and of the two new data sets. The number of data is equal to 20491 and the bending-rotation theoretical approach will be used for the energy level calculation.