title: Photo-induced reactions from efficient molecular dynamics with electronic transitions using the FIREBALL local-orbital density functional theory formalism.
abstract: The computational simulation of photo-induced processes in large molecular systems is a very challenging problem. Firstly, to properly simulate photo-induced reactions the potential energy surfaces corresponding to excited states must be appropriately accessed; secondly, understanding the mechanisms of these processes requires the exploration of complex configurational spaces and the localization of conical intersections; finally, photo-induced reactions are probability events, that require the simulation of hundreds of trajectories to obtain the statistical information for the analysis of the reaction profiles. Here, we present a detailed description of our implementation of a molecular dynamics with electronic transitions algorithm within the local-orbital density functional theory code FIREBALL, suitable for the computational study of these problems. As an example of the application of this approach, we also report results on the [2 + 2] cycloaddition of ethylene with maleic anhydride and on the [2 + 2] photo-induced polymerization reaction of two C60 molecules. We identify different deactivation channels of the initial electron excitation, depending on the time of the electronic transition from LUMO to HOMO, and the character of the HOMO after the transition.
authors: Institute of Physic, Academy of Sciences of the Czech Republic, Cukrovarnická 10, CZ-16200 Prague, Czech Republic. Department of Physical Electronics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Czech Republic.
authors: Vladimír
authors: V
authors: Zobač
authors: James P
authors: JP
authors: Lewis
authors: Enrique
authors: E
authors: Abad
authors: Jesús I
authors: JI
authors: Mendieta-Moreno
authors: Prokop
authors: P
authors: Hapala
authors: Pavel
authors: P
authors: Jelínek
authors: José
authors: J
authors: Ortega
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004581:Electronics; D004583:Electrons; D005030:Ethylenes / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D008027:Light; D008299:Maleic Anhydrides / Q000737:chemistry*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D005030:Ethylenes; D037741:Fullerenes; D008299:Maleic Anhydrides; C036216:ethylene; C069837:fullerene C60