title: Nonadiabatic deactivation of 9H-adenine: a comprehensive picture based on mixed quantum-classical dynamics.
abstract: Mixed quantum-classical dynamics simulations at the multireference configuration interaction (MR-CIS) level were performed for 9 H-adenine in order to understand its ultrafast nonradiative decay process. Dynamics simulations were also performed for the model system 6-aminopyrimidine. MR-CIS and complete active space perturbation theory (CASPT2) have been employed to characterize a large variety of qualitatively different conical intersections, the branches of the crossing seam connecting them, and the reaction paths from the Franck-Condon region for 9 H-adenine. The results show a two-step process consisting of ultrashort deactivation from S 3 to S 1 and a longer exponential decay step corresponding to the conversion from S 1 to S 0.
authors.affiliation: Institute for Theoretical Chemistry, University of Vienna, Waehringerstrasse 17, 1090-Vienna, Austria. mario.barbatti@univie.ac.at
authors.forename: Mario
authors.initials: M
authors.lastname: Barbatti
authors.forename: Hans
authors.initials: H
authors.lastname: Lischka
mesh_terms: D000225:Adenine / Q000737:chemistry*; D003198:Computer Simulation; D008958:Models, Molecular; D008968:Molecular Conformation; D011743:Pyrimidines / Q000737:chemistry; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D011743:Pyrimidines; D000225:Adenine