Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo.
High quality reference data from diffusion Monte Carlo calculations are presented for bulk sI methane hydrate, a complex crystal exhibiting both hydrogen-bond and dispersion dominated interactions. The performance of some commonly used exchange-correlation functionals and all-atom point charge force...
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ftucl:oai:eprints.ucl.ac.uk.OAI2:1421832 2023-12-24T10:18:32+01:00 Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. Cox, SJ Towler, MD Alfè, D Michaelides, A 2014-05-07 application/pdf https://discovery.ucl.ac.uk/id/eprint/1421832/1/1.4871873.pdf https://discovery.ucl.ac.uk/id/eprint/1421832/ eng eng https://discovery.ucl.ac.uk/id/eprint/1421832/1/1.4871873.pdf https://discovery.ucl.ac.uk/id/eprint/1421832/ open J Chem Phys , 140 (17) , Article 174703. (2014) Article 2014 ftucl 2023-11-27T13:07:29Z High quality reference data from diffusion Monte Carlo calculations are presented for bulk sI methane hydrate, a complex crystal exhibiting both hydrogen-bond and dispersion dominated interactions. The performance of some commonly used exchange-correlation functionals and all-atom point charge force fields is evaluated. Our results show that none of the exchange-correlation functionals tested are sufficient to describe both the energetics and the structure of methane hydrate accurately, while the point charge force fields perform badly in their description of the cohesive energy but fair well for the dissociation energetics. By comparing to ice [Formula: see text], we show that a good prediction of the volume and cohesive energies for the hydrate relies primarily on an accurate description of the hydrogen bonded water framework, but that to correctly predict stability of the hydrate with respect to dissociation to ice [Formula: see text] and methane gas, accuracy in the water-methane interaction is also required. Our results highlight the difficulty that density functional theory faces in describing both the hydrogen bonded water framework and the dispersion bound methane. Article in Journal/Newspaper Methane hydrate University College London: UCL Discovery |
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Open Polar |
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University College London: UCL Discovery |
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ftucl |
language |
English |
description |
High quality reference data from diffusion Monte Carlo calculations are presented for bulk sI methane hydrate, a complex crystal exhibiting both hydrogen-bond and dispersion dominated interactions. The performance of some commonly used exchange-correlation functionals and all-atom point charge force fields is evaluated. Our results show that none of the exchange-correlation functionals tested are sufficient to describe both the energetics and the structure of methane hydrate accurately, while the point charge force fields perform badly in their description of the cohesive energy but fair well for the dissociation energetics. By comparing to ice [Formula: see text], we show that a good prediction of the volume and cohesive energies for the hydrate relies primarily on an accurate description of the hydrogen bonded water framework, but that to correctly predict stability of the hydrate with respect to dissociation to ice [Formula: see text] and methane gas, accuracy in the water-methane interaction is also required. Our results highlight the difficulty that density functional theory faces in describing both the hydrogen bonded water framework and the dispersion bound methane. |
format |
Article in Journal/Newspaper |
author |
Cox, SJ Towler, MD Alfè, D Michaelides, A |
spellingShingle |
Cox, SJ Towler, MD Alfè, D Michaelides, A Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. |
author_facet |
Cox, SJ Towler, MD Alfè, D Michaelides, A |
author_sort |
Cox, SJ |
title |
Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. |
title_short |
Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. |
title_full |
Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. |
title_fullStr |
Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. |
title_full_unstemmed |
Benchmarking the performance of density functional theory and point charge force fields in their description of sI methane hydrate against diffusion Monte Carlo. |
title_sort |
benchmarking the performance of density functional theory and point charge force fields in their description of si methane hydrate against diffusion monte carlo. |
publishDate |
2014 |
url |
https://discovery.ucl.ac.uk/id/eprint/1421832/1/1.4871873.pdf https://discovery.ucl.ac.uk/id/eprint/1421832/ |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
J Chem Phys , 140 (17) , Article 174703. (2014) |
op_relation |
https://discovery.ucl.ac.uk/id/eprint/1421832/1/1.4871873.pdf https://discovery.ucl.ac.uk/id/eprint/1421832/ |
op_rights |
open |
_version_ |
1786207576817401856 |