Benchmarking sampling methodology for calculations of Rayleigh light scattering properties of atmospheric molecular clusters

Teis Joranger, Jens Vive Kildgaard, Solvejg Jørgensen, Jonas Elm, Kurt V Mikkelsen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

We present four different computational methods for benchmarking the sampling and Rayleigh light scattering of atmospheric molecular clusters containing hydrogen bonds. For sampling the cluster configurational space we test both the semi-empirical PM6 and PM7 methods, as well as the density functional ωB97X-D with the 6-31G and 6-31++G(d,p) basis sets. As a model system we study clusters consisting of one hydrogen peroxide molecule (H2O2) and 1-5 water molecules. Hydrogen peroxide is an important constituent in the atmosphere where it acts as an oxidant. We find that all the sampling methods show conformational dissimilarities for the studied (H2O2)(H2O)1-5 clusters. Notably the results for the largest studied (H2O2)(H2O)5 cluster show that the sampling methods perform very differently in finding the same low Gibbs free energy conformers. We consider the magnitude of elastic Rayleigh light scattering of the clusters and how the scattering depends on the number of water molecules in the clusters. We observe that the final Boltzmann averaged Rayleigh scattering is independent of the sampling method and that the inexpensive semi-empirical methods can be applied without loss of accuracy. This implies that Rayleigh scattering is a robust property that does not depend significantly on cluster conformations, but instead mainly on the composition of the cluster.
Original languageEnglish
JournalPhysical Chemistry Chemical Physics
Volume21
Issue number31
Pages (from-to)17274-17287
ISSN1463-9076
DOIs
Publication statusPublished - 2019

Cite this

@article{7ad5b7f4bd964361ac7d80cd5e9d23b4,
title = "Benchmarking sampling methodology for calculations of Rayleigh light scattering properties of atmospheric molecular clusters",
abstract = "We present four different computational methods for benchmarking the sampling and Rayleigh light scattering of atmospheric molecular clusters containing hydrogen bonds. For sampling the cluster configurational space we test both the semi-empirical PM6 and PM7 methods, as well as the density functional ωB97X-D with the 6-31G and 6-31++G(d,p) basis sets. As a model system we study clusters consisting of one hydrogen peroxide molecule (H2O2) and 1-5 water molecules. Hydrogen peroxide is an important constituent in the atmosphere where it acts as an oxidant. We find that all the sampling methods show conformational dissimilarities for the studied (H2O2)(H2O)1-5 clusters. Notably the results for the largest studied (H2O2)(H2O)5 cluster show that the sampling methods perform very differently in finding the same low Gibbs free energy conformers. We consider the magnitude of elastic Rayleigh light scattering of the clusters and how the scattering depends on the number of water molecules in the clusters. We observe that the final Boltzmann averaged Rayleigh scattering is independent of the sampling method and that the inexpensive semi-empirical methods can be applied without loss of accuracy. This implies that Rayleigh scattering is a robust property that does not depend significantly on cluster conformations, but instead mainly on the composition of the cluster.",
author = "Teis Joranger and Kildgaard, {Jens Vive} and Solvejg J{\o}rgensen and Jonas Elm and Mikkelsen, {Kurt V}",
year = "2019",
doi = "10.1039/c9cp02573a",
language = "English",
volume = "21",
pages = "17274--17287",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "31",

}

Benchmarking sampling methodology for calculations of Rayleigh light scattering properties of atmospheric molecular clusters. / Joranger, Teis; Kildgaard, Jens Vive; Jørgensen, Solvejg; Elm, Jonas; Mikkelsen, Kurt V.

In: Physical Chemistry Chemical Physics, Vol. 21, No. 31, 2019, p. 17274-17287.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Benchmarking sampling methodology for calculations of Rayleigh light scattering properties of atmospheric molecular clusters

AU - Joranger, Teis

AU - Kildgaard, Jens Vive

AU - Jørgensen, Solvejg

AU - Elm, Jonas

AU - Mikkelsen, Kurt V

PY - 2019

Y1 - 2019

N2 - We present four different computational methods for benchmarking the sampling and Rayleigh light scattering of atmospheric molecular clusters containing hydrogen bonds. For sampling the cluster configurational space we test both the semi-empirical PM6 and PM7 methods, as well as the density functional ωB97X-D with the 6-31G and 6-31++G(d,p) basis sets. As a model system we study clusters consisting of one hydrogen peroxide molecule (H2O2) and 1-5 water molecules. Hydrogen peroxide is an important constituent in the atmosphere where it acts as an oxidant. We find that all the sampling methods show conformational dissimilarities for the studied (H2O2)(H2O)1-5 clusters. Notably the results for the largest studied (H2O2)(H2O)5 cluster show that the sampling methods perform very differently in finding the same low Gibbs free energy conformers. We consider the magnitude of elastic Rayleigh light scattering of the clusters and how the scattering depends on the number of water molecules in the clusters. We observe that the final Boltzmann averaged Rayleigh scattering is independent of the sampling method and that the inexpensive semi-empirical methods can be applied without loss of accuracy. This implies that Rayleigh scattering is a robust property that does not depend significantly on cluster conformations, but instead mainly on the composition of the cluster.

AB - We present four different computational methods for benchmarking the sampling and Rayleigh light scattering of atmospheric molecular clusters containing hydrogen bonds. For sampling the cluster configurational space we test both the semi-empirical PM6 and PM7 methods, as well as the density functional ωB97X-D with the 6-31G and 6-31++G(d,p) basis sets. As a model system we study clusters consisting of one hydrogen peroxide molecule (H2O2) and 1-5 water molecules. Hydrogen peroxide is an important constituent in the atmosphere where it acts as an oxidant. We find that all the sampling methods show conformational dissimilarities for the studied (H2O2)(H2O)1-5 clusters. Notably the results for the largest studied (H2O2)(H2O)5 cluster show that the sampling methods perform very differently in finding the same low Gibbs free energy conformers. We consider the magnitude of elastic Rayleigh light scattering of the clusters and how the scattering depends on the number of water molecules in the clusters. We observe that the final Boltzmann averaged Rayleigh scattering is independent of the sampling method and that the inexpensive semi-empirical methods can be applied without loss of accuracy. This implies that Rayleigh scattering is a robust property that does not depend significantly on cluster conformations, but instead mainly on the composition of the cluster.

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DO - 10.1039/c9cp02573a

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VL - 21

SP - 17274

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SN - 1463-9076

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