Charge migration through DNA molecules in the presence of mismatches
M. H. Lee, S. Avdoshenko, R. Gutiérrez, and G. Cuniberti
Physical Review B 82, 155455 (2010)
Charge transport characteristics of short double-strand (ds) DNA including mismatches are stud- ied within a methodology combining molecular dynamics (MD) simulations and electronic structure calculations based on a fragment orbital approach. Electronic parameters and transmission prob- abilities are computed along the MD trajectory. We find that in the course of the MD simulation the energetic position of frontier orbitals may be interchanged. As a result, the highest occupied molecular orbital (HOMO) can temporarily have a large weight on the backbones as a function of time. This shows that care must be taken when projecting the electronic structure onto effective low-dimensional model Hamiltonians to calculate transport properties. Further, the transport cal- culations indicate a suppression of the charge migration efficiency when introducing a single GT or AC mismatch in the DNA sequence.