Europhys. Lett.
Volume 72, Number 2, October 2005
Page(s) 228 - 234
Section Atomic and molecular physics
Published online 14 September 2005
Europhys. Lett., 72 (2), pp. 228-234 (2005)
DOI: 10.1209/epl/i2005-10227-7

Ionization of metal atoms following valence-excitation of neighbouring molecules

K. Gokhberg1, A. B. Trofimov2, T. Sommerfeld3 and L. S. Cederbaum1

1  Theoretische Chemie, Physicalisch-Chemisches Institut, Universität Heidelberg Im Neuenheimer Feld 229, D-69120 Heidelberg, Germany
2  Laboratory of Quantum Chemistry, Computer Centre, Irkutsk State University 664003 Irkutsk, Russian Federation
3  Department of Chemistry, Chevron Science Center - Pittsburgh, PA 15260, USA

received 30 June 2005; accepted in final form 18 August 2005
published online 14 September 2005

A new relaxation pathway of optically allowed valence-excitations in molecules bound to metal atoms was investigated. We show that the $\sigma_{non}\pi^{\ast}$ excitation of HCN in MgnHCN (n=1,2) clusters decays through the emission of an electron from the metallic component. The calculated lifetimes are of the order of 140$\un{fs}$ for MgHCN and 25$\un{fs}$ for Mg2HCN. These short lifetimes suggest that the relaxation mechanism discussed here should dominate for molecules adsorbed on metal clusters or surfaces. We find that at large distances this decay is dominated by energy transfer.

34.50.Gb - Electronic excitation and ionization of molecules; intermediate molecular states (including lifetimes, state mixing, etc.).
36.40.Cg - Electronic and magnetic properties of clusters.

© EDP Sciences 2005