The infrared predissociation spectra of water clusters

Infrared predissociation spectra of water clusters have been measured in the frequency range 3000-3800 cm^-1 using a molecular beam-color center laser apparatus. The transition from a spectrum resembling that of liquid water to that of the dimer is clearly seen. Detailed theoretical analyses using normal mode theory, local mode theory, and a quantum simulation method are used to interpret the spectrum in terms of a potential surface that includes both intramolecular and intermolecular degrees of freedom.