title: Electric field fluctuations drive vibrational dephasing in water.
abstract: We present a microscopic description of the vibrational spectroscopy of the OH stretch of HOD in liquid D(2)O. Our model predicts that OH frequency correlations decay with a sharp and rapid ( approximately 35 fs) decrease, followed by a beat at approximately 125 fs from intermolecular oxygen vibrations. On a short time scale ( approximately 200 fs), ultrafast infrared spectroscopy of the OH stretch is sensitive to localized intermolecular motions. For times longer than approximately 200 fs, cooperative molecular rearrangements drive dephasing. The interplay of electric field fluctuations, both local and cooperative, dictate vibrational frequency shifts and destroy vibrational coherence in water.
authors.affiliation: Department of Chemistry and George Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Joel D
authors.initials: JD
authors.lastname: Eaves
authors.forename: Andrei
authors.initials: A
authors.lastname: Tokmakoff
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Geissler
mesh_terms: D003198:Computer Simulation; D017666:Deuterium Oxide / Q000737:chemistry; D006860:Hydrogen Bonding; D008956:Models, Chemical; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared / Q000379:methods; D013997:Time Factors; D014732:Vibration; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D017666:Deuterium Oxide