Time‐dependent density functional theory study on direction‐dependent electron and hole transfer processes in molecular systems

Abstract

We report on real-time time-dependent density functional theory calculations on direction-dependent electron and hole transfer processes in molecular systems. As a model system, we focus on α-sulfur. It is shown that time scale of the electron transfer process from a negatively charged S molecule to a neighboring neutral monomer is comparable to that of a strong infrared-active molecular vibrations of the dimer with one negatively charged monomer. This results in a strong coupling between the electrons and the nuclei motion which eventually leads to S ring opening before the electron transfer process is completed. The open-ring structure is found to be stable. The similar infrared-active peak in the case of hole transfer, however, is shown to be very weak and hence no significant scattering by the nuclei is possible. The presented approach to study the charge transfer processes in sulfur has direct applications in the increasingly growing research field of charge transport in molecular systems. © 2017 Wiley Periodicals, Inc.

RT-TDDFT study of hole oscillations in B-DNA monomers and dimers

“…In addition, the determination of many-particle eigenstates is avoided, and the calculation is reduced to an independent particle problem carried out in real time [26]. Recently, RT-TDDFT was applied [27] to study the charge transfer between the oxidized or reduced a-sulfur monomers and the neighbouring neutral ones. Another recent work used RT-TDDFT to study electron transfer through oligo-p-phenylenevinylene (OPV) and carbon bridged OPV (COPV) [28].…”

In silico Complexes of Amino Acids and Diamondoids

“…The CAM-B3LYP hybrid, range-separated functional ensures the correct asymptotic behavior of the exchange energy and has been successfully applied to study long-range charge transfer processes between neighboring molecules. [34][35][36][37][38] Particularly, the empirical parameters in CAM-B3LYP have been originally optimized to predict, among other properties, correct charge-transfer excited state energies. [33] Additionally, to correctly account for charge transfer processes in anions, it is generally important to use diffuse functions in the employed basis sets, like the one used in this work for optical and charge transfer calculations, i. e. 6-31 + G(d).…”

“…All optical and charge‐transfer properties were investigated using the linear‐response time‐dependent DFT (LR‐TDDFT) using the CAM‐B3LYP functional with the 6‐31+G(d) basis set. The CAM‐B3LYP hybrid, range‐separated functional ensures the correct asymptotic behavior of the exchange energy and has been successfully applied to study long‐range charge transfer processes between neighboring molecules . Particularly, the empirical parameters in CAM‐B3LYP have been originally optimized to predict, among other properties, correct charge‐transfer excited state energies .…”

Optoelectronic Properties of Diamondoid-DNA Complexes

“…Herein, we study the electron transfer processes between the diamondoid and the nucleotides using a real-time approach to the TDDFT (RT-TDDFT) as implemented in NWChem . The RT-TDDFT method has been successfully employed to investigate the charge transfer between organic and inorganic molecules. , The Ahlrichs Coulomb fitting basis set is used in the RT-TDDFT simulations to compute the Coulomb part of the Fock matrix . The initial charge configurations of the complexes are constructed by combining the ground-state molecular orbitals of separate individual molecules, where one of the molecules has a −1.0 charge, while the other is neutral.…”