title: Fast ortho-para conversion of H2 adsorbed at copper surface step atoms.
abstract: Ortho-para conversion of H2 adsorbed at the step atoms of a Cu(510) surface proceeds with a short conversion time constant around 1 s as observed in electron-energy-loss measurements of rotational populations. We suggest that this rapid conversion is related to the special character of the adsorption state, which involves a short H2-Cu bond length of 1.8 A. On the flat Cu(100) surface, conversion is found to occur at active sites, most likely step atoms.
authors.affiliation: Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Svensson
authors.forename: S
authors.initials: S
authors.lastname: Andersson