title: Investigation of terahertz vibration-rotation tunneling spectra for the water octamer.
abstract: We report a combined theoretical and experimental study of the water octamer-h16. The calculations used the ring-polymer instanton method to compute tunnelling paths and splittings in full dimensionality. The experiments measured extensive high resolution spectra near 1.4 THz, for which isotope dilution experiments and group theoretical analysis support assignment to the octamer. Transitions appear as singlets, consistent with the instanton paths, which involve the breakage of two hydrogen-bonds and thus give tunneling splittings below experimental resolution.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom.
authors.forename: Jeremy O
authors.initials: JO
authors.lastname: Richardson
authors.forename: David J
authors.initials: DJ
authors.lastname: Wales
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Althorpe
authors.forename: Ryan P
authors.initials: RP
authors.lastname: McLaughlin
authors.forename: Mark R
authors.initials: MR
authors.lastname: Viant
authors.forename: Orion
authors.initials: O
authors.lastname: Shih
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Saykally