title: Spectroscopic signatures of proton transfer dynamics in the water dimer cation.
abstract: Using full-dimensional EOM-IP-CCSD/aug-cc-pVTZ potential energy surfaces, the photoelectron spectrum, vibrational structure, and ionization dynamics of the water dimer radical cation, (H(2)O)(2) (+), were computed. We also report an experimental photoelectron spectrum which is derived from photoionization efficiency measurements and compares favorably with the theoretical spectrum. The vibrational structure is also compared to the recent experimental work of Gardenier et al. [J. Phys. Chem. A 113, 4772 (2009)] and the recent theoretical calculations by Cheng et al. [J. Phys. Chem. A 113, 13779 (2009)]. A reduced-dimensionality nuclear Hamiltonian was used to compute the ionization dynamics for both the ground state and first excited state of the cation. The dynamics show markedly different behavior and spectroscopic signatures depending on which state of the cation is accessed by the ionization. Ionization to the ground state cation surface induces a hydrogen transfer which is complete within 50 fs, whereas ionization to the first excited state results in a much slower process.
authors.affiliation: Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
authors.forename: Eugene
authors.initials: E
authors.lastname: Kamarchik
authors.forename: Oleg
authors.initials: O
authors.lastname: Kostko
authors.forename: Joel M
authors.initials: JM
authors.lastname: Bowman
authors.forename: Musahid
authors.initials: M
authors.lastname: Ahmed
authors.forename: Anna I
authors.initials: AI
authors.lastname: Krylov
mesh_terms: D002412:Cations / Q000737:chemistry; D003198:Computer Simulation; D019281:Dimerization; D011522:Protons; D013057:Spectrum Analysis; D013499:Surface Properties; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D002412:Cations; D011522:Protons; D014867:Water