Nonadiabatic MD simulations of IBr(CO2)n photodissociation

PHYS 443

Matthew A. Thompson, thompsma@colorado.edu1, Jack Barbera, jack.barbera@colorado.edu1, Vladimir Dribinski1, Joshua P. Martin1, Annette Svendsen2, W. Carl Lineberger1, and Robert Parson, rparson@jila.Colorado.edu1. (1) JILA and Department of Chemistry, University of Colorado, 440 UCB, Boulder, CO 80309-0440, (2) Department of Physics and Astronomy, University of Aarhus, Aarhus, Denmark
Potential energy curves for the ground and valence excited states of IBr have been calculated at the MRCI level using the MOLPRO ab initio package. Spin-orbit coupling was calculated via a spin-orbit ECP. Charge densities, transition moments, and nonadiabatic coupling matrix elements constructed from a distributed multipole analysis of the ab initio wavefunctions[1] were then used to carry out nonadiabatic molecular dynamics simulations of the photodissociation of IBr in CO2 clusters. Experimental studies have demonstrated a large variation in ground-state recombination times which are supported by our simulations. We propose a mechanism of excited-state trapping and a configurational transition state which leads to recombination times on the order of 10-20 ps for n=5, 13 up to 1 ns for n=8, 10.

[1] Maslen, Faeder and Parson, Molecular Physics, 1998

 

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006