Transport coefficients from Einstein–Helfand relations using standard and energy-conserving dissipative particle dynamics methods

0571358 - ÚCHP 2024 RIV GB eng J - Článek v odborném periodiku
Malaspina, D.C. - Lísal, Martin - Larentzos, J.P. - Brennan, J.K. - Mackie, A.D. - Avalos, J.B.
Transport coefficients from Einstein–Helfand relations using standard and energy-conserving dissipative particle dynamics methods.
Physical Chemistry Chemical Physics. Roč. 25, č. 17 (2023), s. 12025-12040. ISSN 1463-9076. E-ISSN 1463-9084
Grant ostatní: ARF(ES) W911NF-20-2-0227; ARF(ES) W911NF-20-2-0203; ERDF(ES) PID2021-122187NB-C33
Institucionální podpora: RVO:67985858
Klíčová slova: molecular dynamics * irreversible processes * statistical-mechanics
Obor OECD: Physical chemistry
Impakt faktor: 3.3, rok: 2022
Způsob publikování: Omezený přístup

In this article we demonstrate that contrary to general belief, the standard Einstein-Helfand (EH) formulas are valid for the evaluation of transport coefficients of systems containing dissipative and random forces provided that for these mesoscopic systems: (i) the corresponding conservation laws are satisfied, and (ii) the transition probabilities satisfy detailed balance. Dissipative particle dynamics (DPD) and energy-conserving DPD methods (DPDE), for instance, are archetypical of such mesoscopic approaches satisfying these properties. To verify this statement, we have derived a mesoscopic heat flux form for the DPDE method, suitable for the calculation of the thermal conductivity from an EH expression. We have compared EH measurements against non-equilibrium simulation values for different scenarios, including many-body potentials, and have found excellent agreement in all cases. The expressions are valid notably for systems with density- and temperature-dependent potentials, such as the recently developed generalised DPDE method (GenDPDE) [Avalos et al., Phys. Chem. Chem. Phys., 2019, 21, 24891]. We thus demonstrate that traditional EH formulas in equilibrium simulations can be widely used to obtain transport coefficients, provided that the appropriate expression for the associated flux is used.
Trvalý link: https://hdl.handle.net/11104/0342599