title: Quantum dynamics of proton migration in H2O dications: H2+ formation on ultrafast timescales.
abstract: Irradiation of isolated water molecules by few-cycle pulses of intense infrared laser light can give rise to ultrafast rearrangement resulting in formation of the H(2) (+) ion. Such unimolecular reactions occur on the potential energy surface of the H(2)O(2+) dication that is accessed when peak laser intensities in the 10(15) W cm(-2) range and pulse durations as short as 9-10 fs are used; ion yields of ~1.5% relative to the H(2)O(+) ion are measured. We also study such reactions by means of time-dependent wavepacket dynamics on an ab initio potential energy surface of the dication and show that a proton, generated from O-H bond rupture, migrates towards the H-atom, and forms vibrationally excited H(2)(+) in a well-defined spatial zone.
authors.affiliation: Indian Institute of Science Education and Research Kolkata, Mohanpur 741 252, India.
authors.forename: Manish
authors.initials: M
authors.lastname: Garg
authors.forename: Ashwani K
authors.initials: AK
authors.lastname: Tiwari
authors.forename: Deepak
authors.initials: D
authors.lastname: Mathur
mesh_terms: D002412:Cations / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D011522:Protons; D011789:Quantum Theory; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D002412:Cations; D011522:Protons; D014867:Water; D006859:Hydrogen