One-dimensional embedded cluster approach to modeling CdS nanowires

J. Buckeridge, S. T. Bromley, A. Walsh, S. M. Woodley, C. R. A. Catlow, A. A. Sokol

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We present an embedded cluster model to treat one-dimensional nanostructures, using a hybrid quantum mechanical/molecular mechanical (QM/MM) approach. A segment of the nanowire (circa 50 atoms) is treated at a QM level of theory, using density functional theory (DFT) with a hybrid exchange-correlation functional. This segment is then embedded in a further length of wire, treated at an MM level of theory. The interaction between the QM and MM regions is provided by an embedding potential located at the interface. Point charges are placed beyond the ends of the wire segment in order to reproduce the Madelung potential of the infinite system. We test our model on the ideal system of a CdS linear chain, benchmarking our results against calculations performed on a periodic system using a plane-wave DFT approach, with electron exchange and correlation treated at the same level of approximation in both methods. We perform our tests on pure CdS and, importantly, the system containing a single In or Cu impurity. We find excellent agreement in the determined electronic structure using the two approaches, validating our embedded cluster model. As the hybrid QM/MM model avoids spurious interactions between charged defects, it will be of benefit to the analysis of the role of defects in nanowire materials, which is currently a major challenge using a plane-wave DFT approach. Other advantages of the hybrid QM/MM approach over plane-wave DFT include the ability to calculate ionization energies with an absolute reference and access to high levels of theory for the QM region which are not incorporated in most plane-wave codes. Our results concur with available experimental data.
Original languageEnglish
Article number124101
JournalJournal of Chemical Physics
Volume139
Issue number12
Early online date23 Sep 2013
DOIs
Publication statusPublished - 2013

Fingerprint

Nanowires
Density functional theory
plane waves
nanowires
density functional theory
wire
Wire
Defects
Ionization potential
Time varying systems
defects
Benchmarking
embedding
Electronic structure
Nanostructures
interactions
Impurities
electronic structure
ionization
impurities

Cite this

Buckeridge, J., Bromley, S. T., Walsh, A., Woodley, S. M., Catlow, C. R. A., & Sokol, A. A. (2013). One-dimensional embedded cluster approach to modeling CdS nanowires. Journal of Chemical Physics, 139(12), [124101]. https://doi.org/10.1063/1.4820415

One-dimensional embedded cluster approach to modeling CdS nanowires. / Buckeridge, J.; Bromley, S. T.; Walsh, A.; Woodley, S. M.; Catlow, C. R. A.; Sokol, A. A.

In: Journal of Chemical Physics, Vol. 139, No. 12, 124101, 2013.

Research output: Contribution to journalArticle

Buckeridge, J, Bromley, ST, Walsh, A, Woodley, SM, Catlow, CRA & Sokol, AA 2013, 'One-dimensional embedded cluster approach to modeling CdS nanowires', Journal of Chemical Physics, vol. 139, no. 12, 124101. https://doi.org/10.1063/1.4820415
Buckeridge J, Bromley ST, Walsh A, Woodley SM, Catlow CRA, Sokol AA. One-dimensional embedded cluster approach to modeling CdS nanowires. Journal of Chemical Physics. 2013;139(12). 124101. https://doi.org/10.1063/1.4820415
Buckeridge, J. ; Bromley, S. T. ; Walsh, A. ; Woodley, S. M. ; Catlow, C. R. A. ; Sokol, A. A. / One-dimensional embedded cluster approach to modeling CdS nanowires. In: Journal of Chemical Physics. 2013 ; Vol. 139, No. 12.
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