Charge transport through bio-molecular wires in a solvent: Bridging molecular dynamics and model Hamiltonian approaches

TL;DR

This paper introduces a hybrid quantum/classical simulation method combining molecular dynamics and model Hamiltonians to study charge transport in bio-molecular wires within solvents, emphasizing DNA conformational effects.

Contribution

It develops a novel approach linking molecular dynamics with model Hamiltonians to accurately capture solvent and conformational influences on charge transport.

Findings

DNA conformational fluctuations significantly affect charge transport.

The method successfully models solvent and structural effects on bio-molecular wires.

Application to DNA oligomers demonstrates the importance of dynamics in transport properties.

Abstract

We present a hybrid method based on a combination of quantum/classical molecular dynamics (MD) simulations and a mod el Hamiltonian approach to describe charge transport through bio-molecular wires with variable lengths in presence o f a solvent. The core of our approach consists in a mapping of the bio-molecular electronic structure, as obtained f rom density-functional based tight-binding calculations of molecular structures along MD trajectories, onto a low di mensional model Hamiltonian including the coupling to a dissipative bosonic environment. The latter encodes fluctuat ion effects arising from the solvent and from the molecular conformational dynamics. We apply this approach to the c ase of pG-pC and pA-pT DNA oligomers as paradigmatic cases and show that the DNA conformational fluctuations are essential in determining and supporting charge transport.