Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations
The quantum Monte Carlo (QMC) technique is used to generate accurate energy benchmarks for methane-water clusters containing a single methane monomer and up to 20 water monomers. The benchmarks for each type of cluster are computed for a set of geometries drawn from molecular dynamics simulations. T...
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craippubl:10.1063/1.4926444 2024-02-11T10:05:49+01:00 Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations Gillan, M. J. Alfè, D. Manby, F. R. U.S. Department of Energy 2015 http://dx.doi.org/10.1063/1.4926444 http://aip.scitation.org/doi/am-pdf/10.1063/1.4926444 https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.4926444/15502689/102812_1_online.pdf en eng AIP Publishing The Journal of Chemical Physics volume 143, issue 10 ISSN 0021-9606 1089-7690 Physical and Theoretical Chemistry General Physics and Astronomy journal-article 2015 craippubl https://doi.org/10.1063/1.4926444 2024-01-26T09:45:52Z The quantum Monte Carlo (QMC) technique is used to generate accurate energy benchmarks for methane-water clusters containing a single methane monomer and up to 20 water monomers. The benchmarks for each type of cluster are computed for a set of geometries drawn from molecular dynamics simulations. The accuracy of QMC is expected to be comparable with that of coupled-cluster calculations, and this is confirmed by comparisons for the CH4-H2O dimer. The benchmarks are used to assess the accuracy of the second-order Møller-Plesset (MP2) approximation close to the complete basis-set limit. A recently developed embedded many-body technique is shown to give an efficient procedure for computing basis-set converged MP2 energies for the large clusters. It is found that MP2 values for the methane binding energies and the cohesive energies of the water clusters without methane are in close agreement with the QMC benchmarks, but the agreement is aided by partial cancelation between 2-body and beyond-2-body errors of MP2. The embedding approach allows MP2 to be applied without loss of accuracy to the methane hydrate crystal, and it is shown that the resulting methane binding energy and the cohesive energy of the water lattice agree almost exactly with recently reported QMC values. Article in Journal/Newspaper Methane hydrate AIP Publishing The Journal of Chemical Physics 143 10 |
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language |
English |
topic |
Physical and Theoretical Chemistry General Physics and Astronomy |
spellingShingle |
Physical and Theoretical Chemistry General Physics and Astronomy Gillan, M. J. Alfè, D. Manby, F. R. Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations |
topic_facet |
Physical and Theoretical Chemistry General Physics and Astronomy |
description |
The quantum Monte Carlo (QMC) technique is used to generate accurate energy benchmarks for methane-water clusters containing a single methane monomer and up to 20 water monomers. The benchmarks for each type of cluster are computed for a set of geometries drawn from molecular dynamics simulations. The accuracy of QMC is expected to be comparable with that of coupled-cluster calculations, and this is confirmed by comparisons for the CH4-H2O dimer. The benchmarks are used to assess the accuracy of the second-order Møller-Plesset (MP2) approximation close to the complete basis-set limit. A recently developed embedded many-body technique is shown to give an efficient procedure for computing basis-set converged MP2 energies for the large clusters. It is found that MP2 values for the methane binding energies and the cohesive energies of the water clusters without methane are in close agreement with the QMC benchmarks, but the agreement is aided by partial cancelation between 2-body and beyond-2-body errors of MP2. The embedding approach allows MP2 to be applied without loss of accuracy to the methane hydrate crystal, and it is shown that the resulting methane binding energy and the cohesive energy of the water lattice agree almost exactly with recently reported QMC values. |
author2 |
U.S. Department of Energy |
format |
Article in Journal/Newspaper |
author |
Gillan, M. J. Alfè, D. Manby, F. R. |
author_facet |
Gillan, M. J. Alfè, D. Manby, F. R. |
author_sort |
Gillan, M. J. |
title |
Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations |
title_short |
Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations |
title_full |
Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations |
title_fullStr |
Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations |
title_full_unstemmed |
Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations |
title_sort |
energy benchmarks for methane-water systems from quantum monte carlo and second-order møller-plesset calculations |
publisher |
AIP Publishing |
publishDate |
2015 |
url |
http://dx.doi.org/10.1063/1.4926444 http://aip.scitation.org/doi/am-pdf/10.1063/1.4926444 https://pubs.aip.org/aip/jcp/article-pdf/doi/10.1063/1.4926444/15502689/102812_1_online.pdf |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
The Journal of Chemical Physics volume 143, issue 10 ISSN 0021-9606 1089-7690 |
op_doi |
https://doi.org/10.1063/1.4926444 |
container_title |
The Journal of Chemical Physics |
container_volume |
143 |
container_issue |
10 |
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1790603014276382720 |