# Partial vs. integer electron transfer in molecular assemblies: On the importance of multideterminant theoretical description and the necessity to find a solution within DFT

## Abstract

Nonequilibrium Green's function techniques (NEGF) combined with density functional theory (DFT) calculations have become a standard tool for the description of electron transport through single molecule nanojunctions in the coherent tunneling (CT) regime. However, the applicability of these methods for transport in the Coulomb blockade (CB) regime is questionable. For a molecular assembly model, with multideterminant calculations as a benchmark, we show how a closed-shell ansatz, the usual ingredient of mean-field methods, fails to properly describe the step like electron-transfer characteristic in weakly coupled systems. Detailed analysis of this misbehavior allows us to propose a practical scheme to extract the addition energies in the CB regime for single-molecule junctions from NEGF DFT within the local-density approximation (closed shell). We show also that electrostatic screening effects are taken into account within this simple approach.

- Authors:

- Laboratory for Chemistry of Novel Materials, University of Mons, Place du Parc 20, B-7000 Mons (Belgium)
- Department of Physical Chemistry, University of Vienna, Sensengasse 8/7, A-1090 Vienna (Austria)

- Publication Date:

- OSTI Identifier:
- 22390893

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: AIP Conference Proceedings; Journal Volume: 1642; Journal Issue: 1; Conference: ICCMSE-2010: International Conference of Computational Methods in Sciences and Engineering 2010, Kos (Greece), 3-8 Oct 2010; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 74 ATOMIC AND MOLECULAR PHYSICS; APPROXIMATIONS; BENCHMARKS; DENSITY; DENSITY FUNCTIONAL METHOD; ELECTRON TRANSFER; ELECTRONS; GREEN FUNCTION; MATHEMATICAL SOLUTIONS; MEAN-FIELD THEORY; MOLECULES; TUNNEL EFFECT

### Citation Formats

```
Geskin, Victor, Cornil, Jérôme, and Stadler, Robert.
```*Partial vs. integer electron transfer in molecular assemblies: On the importance of multideterminant theoretical description and the necessity to find a solution within DFT*. United States: N. p., 2015.
Web. doi:10.1063/1.4906664.

```
Geskin, Victor, Cornil, Jérôme, & Stadler, Robert.
```*Partial vs. integer electron transfer in molecular assemblies: On the importance of multideterminant theoretical description and the necessity to find a solution within DFT*. United States. doi:10.1063/1.4906664.

```
Geskin, Victor, Cornil, Jérôme, and Stadler, Robert. Thu .
"Partial vs. integer electron transfer in molecular assemblies: On the importance of multideterminant theoretical description and the necessity to find a solution within DFT". United States.
doi:10.1063/1.4906664.
```

```
@article{osti_22390893,
```

title = {Partial vs. integer electron transfer in molecular assemblies: On the importance of multideterminant theoretical description and the necessity to find a solution within DFT},

author = {Geskin, Victor and Cornil, Jérôme and Stadler, Robert},

abstractNote = {Nonequilibrium Green's function techniques (NEGF) combined with density functional theory (DFT) calculations have become a standard tool for the description of electron transport through single molecule nanojunctions in the coherent tunneling (CT) regime. However, the applicability of these methods for transport in the Coulomb blockade (CB) regime is questionable. For a molecular assembly model, with multideterminant calculations as a benchmark, we show how a closed-shell ansatz, the usual ingredient of mean-field methods, fails to properly describe the step like electron-transfer characteristic in weakly coupled systems. Detailed analysis of this misbehavior allows us to propose a practical scheme to extract the addition energies in the CB regime for single-molecule junctions from NEGF DFT within the local-density approximation (closed shell). We show also that electrostatic screening effects are taken into account within this simple approach.},

doi = {10.1063/1.4906664},

journal = {AIP Conference Proceedings},

number = 1,

volume = 1642,

place = {United States},

year = {Thu Jan 22 00:00:00 EST 2015},

month = {Thu Jan 22 00:00:00 EST 2015}

}