title: Interaction of O(-) and H2 at low temperatures.
abstract: Reactive collisions between O(-) and H2 have been studied experimentally at temperatures ranging from 10 K to 300 K using a cryogenic radiofrequency 22-pole ion trap. The rate coefficients for associative detachment, leading to H2O + e(-), increase with decreasing temperature and reach a flat maximum of 1.8 × 10(-9) cm(3) s(-1) at temperatures between 20 K and 80 K. There, the overall reaction probability is in good agreement with a capture model indicating efficient non-adiabatic couplings between the entrance potential energy surfaces. Classical trajectory calculations on newly calculated potential energy surfaces as well as the topology of the conical intersection seam leading to the neutral surface corroborate this. The formation of OH(-) + H via hydrogen transfer, although occurring with a probability of a few percent only (about 5 × 10(-11) cm(3) s(-1) at temperatures 10-300 K), indicates that there are reaction paths, where electron detachment is avoided.
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: P
authors.initials: P
authors.lastname: Jusko
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: Š
authors.initials: Š
authors.lastname: Roučka
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: D
authors.initials: D
authors.lastname: Mulin
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: I
authors.initials: I
authors.lastname: Zymak
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: R
authors.initials: R
authors.lastname: Plašil
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: D
authors.initials: D
authors.lastname: Gerlich
authors.affiliation: Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Čížek
authors.affiliation: Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: K
authors.initials: K
authors.lastname: Houfek
authors.affiliation: Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, Prague 180 00, Czech Republic.
authors.forename: J
authors.initials: J
authors.lastname: Glosík