TY - JOUR
T1 - Partial molar properties from molecular simulation using multiple linear regression
AU - Josephson, Tyler R.
AU - Singh, Ramanish
AU - Minkara, Mona S.
AU - Fetisov, Evgenii O.
AU - Siepmann, J. Ilja
N1 - Publisher Copyright:
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2019/12/17
Y1 - 2019/12/17
N2 - Partial molar volumes, energies, and enthalpies can be computed from NpT-Gibbs ensemble simulations through a post-processing procedure that leverages fluctuations in composition, total volume, and total energy of a simulation box. By recording the instantaneous box volumes V and instantaneous number of molecules (Formula presented.) of each of n species for M frames, a large (Formula presented.) matrix (Formula presented.) is constructed, as well as the (Formula presented.) vector (Formula presented.). The (Formula presented.) vector of partial molar volumes (Formula presented.) may then be solved using (Formula presented.). A similar construction permits calculation of partial molar energies using M instantaneous measurements of the total energy of the simulation box, and (Formula presented.). Partial molar enthalpies may be derived from (Formula presented.), (Formula presented.), and pressure p. These properties may be used to calculate enthalpy and entropy of transfer (absorption, extraction, and adsorption) for species in complex mixtures. The method is demonstrated on three systems in the NpT-Gibbs ensemble: a highly compressible natural gas condensate of methane, n-butane, and n-decane, the liquid-phase adsorption of 1,5-pentanediol and ethanol onto the MFI zeolite, and a relatively incompressible mixture of ethanol, n-dodecane, and water at liquid-liquid equilibrium. Property predictions are compared to those from numerical differentiation of simulation data sequentially changing the composition and from equations of state. The method can also be extended to reaction equilibria in a closed system and is applied to a reactive first-principles Monte Carlo simulation of compressed nitrogen/oxygen.
AB - Partial molar volumes, energies, and enthalpies can be computed from NpT-Gibbs ensemble simulations through a post-processing procedure that leverages fluctuations in composition, total volume, and total energy of a simulation box. By recording the instantaneous box volumes V and instantaneous number of molecules (Formula presented.) of each of n species for M frames, a large (Formula presented.) matrix (Formula presented.) is constructed, as well as the (Formula presented.) vector (Formula presented.). The (Formula presented.) vector of partial molar volumes (Formula presented.) may then be solved using (Formula presented.). A similar construction permits calculation of partial molar energies using M instantaneous measurements of the total energy of the simulation box, and (Formula presented.). Partial molar enthalpies may be derived from (Formula presented.), (Formula presented.), and pressure p. These properties may be used to calculate enthalpy and entropy of transfer (absorption, extraction, and adsorption) for species in complex mixtures. The method is demonstrated on three systems in the NpT-Gibbs ensemble: a highly compressible natural gas condensate of methane, n-butane, and n-decane, the liquid-phase adsorption of 1,5-pentanediol and ethanol onto the MFI zeolite, and a relatively incompressible mixture of ethanol, n-dodecane, and water at liquid-liquid equilibrium. Property predictions are compared to those from numerical differentiation of simulation data sequentially changing the composition and from equations of state. The method can also be extended to reaction equilibria in a closed system and is applied to a reactive first-principles Monte Carlo simulation of compressed nitrogen/oxygen.
KW - Monte Carlo simulation
KW - phase equilibria
KW - reaction equilibria
KW - thermodynamics
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U2 - 10.1080/00268976.2019.1648898
DO - 10.1080/00268976.2019.1648898
M3 - Article
AN - SCOPUS:85076506049
SN - 0026-8976
VL - 117
SP - 3589
EP - 3602
JO - Molecular Physics
JF - Molecular Physics
IS - 23-24
ER -