title: The local structure of protonated water from x-ray absorption and density functional theory.
abstract: We present a combined x-ray absorption spectroscopy/computational study of water in hydrochloric acid (HCl) solutions of varying concentration to address the structure and bonding of excess protons and their effect on the hydrogen bonding network in liquid water. Intensity variations and energy shifts indicate changes in the hydrogen bonding structure in water as well as the local structure of the protonated complex as a function of the concentration of protons. In particular, in highly acidic solutions we find a dominance of the Eigen form, H(3)O(+), while the proton is less localized to a specific water under less acidic conditions.
authors.affiliation: Fysikum, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cavalleri
authors.forename: Lars-Ake
authors.initials: LA
authors.lastname: Näslund
authors.forename: David C
authors.initials: DC
authors.lastname: Edwards
authors.forename: Philippe
authors.initials: P
authors.lastname: Wernet
authors.forename: Hirohito
authors.initials: H
authors.lastname: Ogasawara
authors.forename: Satish
authors.initials: S
authors.lastname: Myneni
authors.forename: Lars
authors.initials: L
authors.lastname: Ojamäe
authors.forename: Michael
authors.initials: M
authors.lastname: Odelius
authors.forename: Anders
authors.initials: A
authors.lastname: Nilsson
authors.forename: Lars G M
authors.initials: LG
authors.lastname: Pettersson