Terahertz VRT Spectroscopy of the Water Tetramer-d8: Combined Analysis of Vibrational Bands at 4.1 THz and 2.0 THz Wei Lin, Jia-xiang Han, Lynelle K. Takahashi, Heather A. Harker, Frank N. Keutsch, Richard J. Saykally Department of Chemistry, University of California, Berkeley, California 94720-1460 June 22, 2007 Columbus, OH

Characterization of Water Clusters

Berkeley Terahertz VRT Spectrometer

The Water Trimer Torsional D2O trimer H2O trimer Translational 142cm-1 Translational ~ 525cm-1 Librational Torsional D2O trimer H2O trimer (Han et al, Talk RA02, 2006)

The Water Trimer (Han et al, Talk RA02, 2006)

The Water Tetramer

Tunneling splittings for vibrational modes of the water tetramer 2 Brown et al. J. Chem. Phys. 1999, 111, 7801

Additional Splittings for K=2 Transitions of the 2.03 THz Band Cruzan et al. Science 1996, 271 59 Cruzan et al. J. Chem. Phys. 1996, 105, 6634

Effective Hamiltonian 2.03 THz parallel band: 4.13 THz perpendicular band: Van der Avoird et al. J. Chem. Phys. 1996, 105 8034 Keutsch et al. Chem. Rev. 2003, 103, 2533

Spectroscopic constants

Vibrational Analysis Schütz et al. J. Chem. Phys. 1995, 103, 6114 Sabo et al. J. Chem. Phys., 1998, 109, 5404 Dunn et al. J. Phys. Chem. A 2006, 110, 303 and private communications

Comparison of the Inertia Defects of the Water Trimer and Tetramer

Acknowledgement Dr. Herbert Pickett (JPL) Prof. Stewart Novick (Wesleyan University) Prof. George Shields (Hamilton College)