Quantum corrected Langevin dynamics for adsorbates on metal surfaces interacting with hot electrons

Thomas Olsen, Jakob Schiøtz
2010 Journal of Chemical Physics  
We investigate the importance of including quantized initial conditions in Langevin dynamics for adsorbates interacting with a thermal reservoir of electrons. For quadratic potentials the time evolution is exactly described by a classical Langevin equation and it is shown how to rigorously obtain quantum mechanical probabilities from the classical phase space distributions resulting from the dynamics. At short time scales, classical and quasiclassical initial conditions lead to wrong results
more » ... only correctly quantized initial conditions give a close agreement with an inherently quantum mechanical master equation approach. With CO on Cu(100) as an example, we demonstrate the effect for a system with ab initio frictional tensor and potential energy surfaces and show that quantizing the initial conditions can have a large impact on both the desorption probability and the distribution of molecular vibrational states.
doi:10.1063/1.3457947 pmid:20649316 fatcat:3rm5r3pvkfa3jmi7nxtfibzbju