Benchmarking calculations of excitonic couplings between bacteriochlorophylls

Kenny, Elise P. and Kassal, Ivan (2016) Benchmarking calculations of excitonic couplings between bacteriochlorophylls. The Journal of Physical Chemistry B, 120 1: 25-32. doi:10.1021/acs.jpcb.5b08817

Author Kenny, Elise P.
Kassal, Ivan
Title Benchmarking calculations of excitonic couplings between bacteriochlorophylls
Journal name The Journal of Physical Chemistry B   Check publisher's open access policy
ISSN 1520-5207
Publication date 2016-01-14
Year available 2015
Sub-type Article (original research)
DOI 10.1021/acs.jpcb.5b08817
Open Access Status Not Open Access
Volume 120
Issue 1
Start page 25
End page 32
Total pages 8
Place of publication Washington, DC United States
Publisher American Chemical Society
Language eng
Abstract Excitonic couplings between (bacterio)chlorophyll molecules are necessary for simulating energy transport in photosynthetic complexes. Many techniques for calculating the couplings are in use, from the simple (but inaccurate) point-dipole approximation to fully quantum-chemical methods. We compared several approximations to determine their range of applicability, noting that the propagation of experimental uncertainties poses a fundamental limit on the achievable accuracy. In particular, the uncertainty in crystallographic coordinates yields an uncertainty of about 20% in the calculated couplings. Because quantum-chemical corrections are smaller than 20% in most biologically relevant cases, their considerable computational cost is rarely justified. We therefore recommend the electrostatic TrEsp method across the entire range of molecular separations and orientations because its cost is minimal and it generally agrees with quantum-chemical calculations to better than the geometric uncertainty. Understanding these uncertainties can guard against striving for unrealistic precision; at the same time, detailed benchmarks can allow important qualitative questions—which do not depend on the precise values of the simulation parameters—to be addressed with greater confidence about the conclusions.
Keyword Chemistry, Physical
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID DE140100433
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mathematics and Physics
Centre for Quantum Computer Technology Publications
Official 2016 Collection
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Citation counts: TR Web of Science Citation Count  Cited 11 times in Thomson Reuters Web of Science Article | Citations
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