Electronic coupling matrix elements from charge constrained density functional theory calculations using a plane wave basis set

Oberhofer, Harald; Blumberger, Jochen

doi:doi:10.1063/1.3507878

Volume/Page
Keyword
DOI
Citation
Advanced

Volume: Page/Article:

Search Content Type

article doi:

Citation:

Effective local potentials for excited states

The constrained variational Hartree–Fock method for excited states of the same symmetry as the ground state [Chem. Phys. Lett. 287, 189 (1998)] is combined with the effective local potential (ELP) method [J. Chem. Phys. 125, 081104 (2006)] to generate Kohn–Sham-type exact-exchange potentials for singly excited states of many-electron systems. Illustrative examples include the three lowest 2S states of the Li and Na atoms and the three lowest 3S states of He and Be. For the systems studied, exci...

Multidimensional optical spectroscopy of a single molecule in a current-carrying state

The nonlinear optical signals from an open system consisting of a molecule connected to metallic leads, in response to a sequence of impulsive pulses, are calculated using a superoperator formalism. Two detection schemes are considered: coherent stimulated emission and incoherent fluorescence. The two provide similar but not identical information. The necessary superoperator correlation functions are evaluated either by converting them to ordinary (Hilbert space) operators which are then expand...

We present a plane wave basis set implementation for the calculation of electronic coupling matrix elements of electron transfer reactions within the framework of constrained density functional theory (CDFT). Following the work of Wu and Van Voorhis [J. Chem. Phys. 125, 164105 (2006)], the diabatic wavefunctions are approximated by the Kohn–Sham determinants obtained from CDFT calculations, and the coupling matrix element calculated by an efficient integration scheme. Our results for intermolecular electron transfer in small systems agree very well with high-level ab initio calculations based on generalized Mulliken–Hush theory, and with previous local basis set CDFT calculations. The effect of thermal fluctuations on the coupling matrix element is demonstrated for intramolecular electron transfer in the tetrathiafulvalene-diquinone (Q-TTF-Q⁻) anion. Sampling the electronic coupling along density functional based molecular dynamics trajectories, we find that thermal fluctuations, in particular the slow bending motion of the molecule, can lead to changes in the instantaneous electron transfer rate by more than an order of magnitude. The thermal average, (〈|H_ab|²〉)^1/2 = 6.7 mH, is significantly higher than the value obtained for the minimum energy structure, |H_ab| = 3.8 mH. While CDFT in combination with generalized gradient approximation (GGA) functionals describes the intermolecular electron transfer in the studied systems well, exact exchange is required for Q-TTF-Q⁻ in order to obtain coupling matrix elements in agreement with experiment (3.9 mH). The implementation presented opens up the possibility to compute electronic coupling matrix elements for extended systems where donor, acceptor, and the environment are treated at the quantum mechanical (QM) level.

Article Outline

INTRODUCTION
THEORY
1. CDFT
2. H _ab from CDFT
3. Calculation of and [Eqs. (12) and (13)]
4. H _ab from FO-DFT
COMPUTATIONAL DETAILS
RESULTS AND DISCUSSION
1. He 2+
2. Zn 2+
3. Benzene–Cl ⁻
4. Dependence of H _ab on the weight function
5. Q-TTF-Q ⁻
CONCLUDING REMARKS

RELATED DATABASES

To view database links for this article, you need to log in.

KEYWORDS and PACS

Keywords

ab initio calculations, charge exchange, density functional theory, fluctuations, intermolecular mechanics, molecular dynamics method, organic compounds, wave functions

PACS

34.70.+e

Charge transfer
34.20.Gj

Intermolecular and atom-molecule potentials and forces
31.15.E-

Density-functional theory
31.15.at

Molecule transport characteristics; molecular dynamics; electronic structure of polymers

ARTICLE DATA

Digital Object Identifier

http://dx.doi.org/10.1063/1.3507878

PUBLICATION DATA

ISSN

0021-9606 (print)

1089-7690 (online)

Publisher

$abstract.society.value is a Member of CrossRef

American Institute of Physics

For access to citing articles, you need to log in.

Figures (7) Tables (3)

Access to article objects (figures, tables, multimedia) requires a subscription; log in to view available files.
(Access to supplementary files, where available, is free for this journal.)