Benchmarking of molecular dynamics force fields for solid–liquid and solid–solid phase transitions in alkanes
Benchmarking of molecular dynamics force fields for solid–liquid and solid–solid phase transitions in alkanes
Accurate prediction of alkane phase transitions involving solids is needed to prevent catastrophic pipeline blockages, improve lubrication formulations, smart insulation, and energy storage, as well as bring fundamental understanding to processes such as artificial morphogenesis. However, simulation of these transitions is challenging and therefore often omitted in force field development. Here, we perform a series of benchmarks on seven representative molecular dynamics models (TraPPE, PYS, CHARMM36, L-OPLS, COMPASS, Williams, and the newly optimized Williams 7B), comparing with experimental data for liquid properties, liquid-solid, and solid-solid phase transitions of two prototypical alkanes, n-pentadecane (C15) and n-hexadecane (C16). We find that existing models overestimate the melting points by up to 34 K, with PYS and Williams 7B yielding the most accurate results deviating only 2 and 3 K from the experiment. We specially design order parameters to identify crystal-rotator phase transitions in alkanes. United-atom models could only produce a rotator phase with complete rotational disorder, whereas all-atom models using a 12-6 Lennard-Jones potential show no rotator phase even when superheated above the melting point. In contrast, Williams (Buckingham potential) and COMPASS (9-6 Lennard-Jones) reproduce the crystal-to-rotator phase transition, with the optimized Williams 7B model having the most accurate crystal-rotator transition temperature of C15.
5145-5159
Burrows, Stephen A.
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Korotkin, Ivan
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Smoukov, Stoyan K.
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Boek, Edo
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Karabasov, Sergey
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20 May 2021
Burrows, Stephen A.
bbcde834-1293-42bc-8c1f-ac213bc0a65d
Korotkin, Ivan
1ca96363-075e-41d9-a0c1-153c8c0cc31a
Smoukov, Stoyan K.
483e95dd-393a-4d2e-b57a-99e75f6dcb70
Boek, Edo
96e7dbb2-75e0-40df-8b21-13a5cd5143ba
Karabasov, Sergey
8c5764f1-8325-47c0-8db7-4565ac15685d
Burrows, Stephen A., Korotkin, Ivan, Smoukov, Stoyan K., Boek, Edo and Karabasov, Sergey
(2021)
Benchmarking of molecular dynamics force fields for solid–liquid and solid–solid phase transitions in alkanes.
The Journal of Physical Chemistry B, 125 (19), .
(doi:10.1021/acs.jpcb.0c07587).
Abstract
Accurate prediction of alkane phase transitions involving solids is needed to prevent catastrophic pipeline blockages, improve lubrication formulations, smart insulation, and energy storage, as well as bring fundamental understanding to processes such as artificial morphogenesis. However, simulation of these transitions is challenging and therefore often omitted in force field development. Here, we perform a series of benchmarks on seven representative molecular dynamics models (TraPPE, PYS, CHARMM36, L-OPLS, COMPASS, Williams, and the newly optimized Williams 7B), comparing with experimental data for liquid properties, liquid-solid, and solid-solid phase transitions of two prototypical alkanes, n-pentadecane (C15) and n-hexadecane (C16). We find that existing models overestimate the melting points by up to 34 K, with PYS and Williams 7B yielding the most accurate results deviating only 2 and 3 K from the experiment. We specially design order parameters to identify crystal-rotator phase transitions in alkanes. United-atom models could only produce a rotator phase with complete rotational disorder, whereas all-atom models using a 12-6 Lennard-Jones potential show no rotator phase even when superheated above the melting point. In contrast, Williams (Buckingham potential) and COMPASS (9-6 Lennard-Jones) reproduce the crystal-to-rotator phase transition, with the optimized Williams 7B model having the most accurate crystal-rotator transition temperature of C15.
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S-Burrows_Benchmarking_of_molecular_dynamics_force_fields_02-2021
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Accepted/In Press date: 8 February 2021
e-pub ahead of print date: 16 March 2021
Published date: 20 May 2021
Identifiers
Local EPrints ID: 450204
URI: http://eprints.soton.ac.uk/id/eprint/450204
ISSN: 1520-6106
PURE UUID: bf6f32b6-e751-44b8-9405-be72eecc5c9e
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Date deposited: 15 Jul 2021 16:41
Last modified: 17 Mar 2024 06:38
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Author:
Stephen A. Burrows
Author:
Stoyan K. Smoukov
Author:
Edo Boek
Author:
Sergey Karabasov
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