Full-electron calculation of effective electronic couplings and excitation energies of charge transfer states: Application to hole transfer in DNA pi-stacks.

Content Provider	Europe PMC
Author	Migliore, Agostino
Copyright Year	2009
Abstract	In this work I develop and apply a theoretical method for calculating effective electronic couplings (or transfer integrals) between redox sites involved in hole or electron transfer reactions. The resulting methodology is a refinement and a generalization of a recently developed approach for transfer integral evaluation. In fact, it holds for any overlap between the charge-localized states used to represent charge transfer (CT) processes in the two-state model. The presented theoretical and computational analyses show that the prototype approach is recovered for sufficiently small overlaps. The method does not involve any empirical parameter. It allows a complete multielectron description, therefore including electronic relaxation effects. Furthermore, its theoretical formulation holds at any value of the given reaction coordinate and yields a formula for the evaluation of the vertical excitation energy (i.e., the energy difference between the adiabatic ground and first-excited electronic states) that rests on the same physical quantities used in transfer integral calculation. In this paper the theoretical approach is applied to CT in B-DNA base dimers within the framework of Density Functional Theory (DFT), although it can be implemented in other computational schemes. The results of this work, as compared with previous Hartree–Fock (HF) and post-HF evaluations, support the applicability of the current implementation of the method to larger π-stacked arrays, where post-HF approaches are computationally unfeasible.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC2766402&blobtype=pdf
ISSN	00219606
Volume Number	131
DOI	10.1063/1.3232007
PubMed Central reference number	PMC2766402
Issue Number	11
PubMed reference number	19778106
Journal	The Journal of Chemical Physics [J Chem Phys]
e-ISSN	10897690
Language	English
Publisher	American Institute of Physics
Publisher Date	2009-09-01
Access Restriction	Open
Rights License	Copyright © 2009 American Institute of Physics
Content Type	Text
Resource Type	Article
Subject	Physics and Astronomy Medicine Physical and Theoretical Chemistry