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MO: Molekülphysik
MO 10: Cluster IV: Molekulare Cluster, Theorie (gemeinsam mit FV Atomphysik)
MO 10.6: Talk
Wednesday, March 6, 2002, 17:45–18:00, HS 01/E01
Molecular dynamics simulations of water clusters scattering from graphite — •Anna Tomsic1, Nikola Markovic2, and Jan B.C. Pettersson3 — 1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 München — 2Department of Physical Chemistry, Chalmers University of Technology, 412 96 Göteborg, Sweden — 3Department of Chemistry, Physical Chemistry, Göteborg University, 412 96 Göteborg, Sweden
Large-scale classical trajectory calculations of (H2O)n, n <= 25159, colliding with a graphite surface at normal incidence have been carried out. The incident velocity ranged from 50 to 2000 ms−1 and the surface temperature was between 300 K and 1400 K. Upon impact, the cluster is deformed elastically (reversibly) and plastically (irreversibly), and if the elastically stored energy is larger than the adhesion energy between the cluster and the surface, the cluster scatters directly from the surface. The partitioning between elastic and plastic deformation is governed by the initial conditions (cluster temperature, incident velocity, incident cluster size and surface temperature). At low incident velocities the scattering probability is controlled by adhesion and at high incident velocities by plastic deformation, and the direct scattering is thus confined to a narrow range of incident velocities. The results are in qualitative agreement with recent experimental studies of water clusters scattering from graphite.