ONIOM approach for non-adiabatic on-the-fly molecular dynamics demonstrated for the backbone controlled Dewar valence isomerization

Journal of Chemical Physics, 2012, http://dx.doi.org/10.1063/1.4720090, Volume 136; Issue 20; Pages 10 published on 25.05.2012
Journal of Chemical Physics, online article
Non-adiabatic on-the-fly molecular dynamics (NA-O-MD) simulations require the electronic wavefunction, energy gradients, and derivative coupling vectors in every timestep. Thus, they are commonly restricted to the excited state dynamics of molecules with up to ≈20 atoms. We discuss an approximation that combines the ONIOM(QM:QM) method with NA-O-MD simulations to allow calculations for larger molecules. As a proof of principle we present the excited state dynamics of a (6-4)-lesion containing dinucleotide (63 atoms), and especially the importance to include the confinement effects of the DNA backbone. The method is able to include electron correlation on a high level of theory and offers an attractive alternative to QM:MM approaches for moderate sized systems with unknown force fields.  

TU München
Helmholtz München
MPI of Neurobiology
MPI of Biochemistry