Charge-Transfer Matrix Elements by FMO-LCMO Approach: Hole Transfer in DNA with Parameter Tuned Range-Separated DFT

TL;DR

This paper introduces a computational scheme combining FMO-LCMO and tuned range-separated DFT to accurately calculate charge-transfer matrix elements, considering environmental effects and orbital relaxation, demonstrated on DNA and benchmark systems.

Contribution

The paper presents a novel method for computing charge-transfer matrix elements that accounts for environmental Coulomb effects and orbital relaxation with low computational cost.

Findings

Accurately computed charge-transfer matrix elements for benchmark systems.

Demonstrated the method's effectiveness on DNA hole transfer systems.

Highlighted the importance of orbital relaxation effects in charge transfer calculations.

Abstract

A scheme for computing charge-transfer matrix elements with the linear combination of fragment molecular orbitals and the 'nonempirically tuned range-separated' density functional is presented. It takes account of the self-consistent orbital relaxation induced by environmental Coulomb field and the exchange interaction in fragment pairs at low computational scaling along the system size. The accuracy was confirmed numerically on benchmark systems of imidazole and furane homo-dimer cations. Applications to hole transfers in DNA nucleobase pairs and in a $\pi$-stack adenine octomer highlight the effects of orbital relaxation.