Green–Kubo expressions for transport coefficients from dissipative particle dynamics simulations revisited

0580367 - ÚCHP 2025 RIV GB eng J - Článek v odborném periodiku
Malaspina, D.C. - Lísal, Martin - Larentzos, J.P. - Brennan, J.K. - Mackie, A.D. - Bonet Avalos, J.
Green–Kubo expressions for transport coefficients from dissipative particle dynamics simulations revisited.
Physical Chemistry Chemical Physics. Roč. 26, č. 2 (2024), s. 1328-1339. ISSN 1463-9076. E-ISSN 1463-9084
Grant ostatní: ARO(US) W911NF-20-2-0227; ARO(US) W911NF-20-2-0203
Institucionální podpora: RVO:67985858
Klíčová slova: conservative * dissipative and random interactions * Einstein–Helfand formulas * stress tensor
Obor OECD: Physical chemistry
Impakt faktor: 3.3, rok: 2022
Způsob publikování: Omezený přístup

This article addresses the debate about the correct application of Green–Kubo expressions for transport coefficients from dissipative particle dynamics simulations. We demonstrate that the Green–Kubo expressions are valid provided that the dynamic model conserves the physical property, whose transport is studied, and the fluctuations satisfy detailed balance. As a result, the traditional expressions used in molecular dynamics can also be applied to dissipative particle dynamics simulations. However, taking the calculation of the shear viscosity as a paradigmatic example, a random contribution, whose strength scales as 1/dt 1/2, with dt the time-step, can cause difficulties if the stress tensor is not separated into the different contributions. We compare our expression to that of Ernst and Brito (M. H. Ernst and R. Brito, Europhys. Lett., 2006, 73, 183–189), which arises from a diametrically different perspective. We demonstrate that the two expressions are completely equivalent and find exactly the same result both analytically and numerically. We show that the differences are not due to the lack of time-reversibility but instead from a preaveraging of the random contributions. Despite the overall validity of Green–Kubo expressions, we find that the Einstein–Helfand relations (D. C. Malaspina et al. Phys. Chem. Chem. Phys., 2023, 25, 12025–12040) do not suffer from the need to decompose the stress tensor and can readily be used with a high degree of accuracy. Consequently, Einstein–Helfand relations should be seen as the preferred method to calculate transport coefficients from dissipative particle dynamics simulations.
Trvalý link: https://hdl.handle.net/11104/0349155