Single-site Lennard-Jones models via polynomial chaos surrogates of Monte Carlo molecular simulation

Ahmad Salim Kadoura, Adil Siripatana, Shuyu Sun, Omar Knio, Ibrahim Hoteit

Research output: Contribution to journalArticlepeer-review


In this work, two Polynomial Chaos (PC) surrogates were generated to reproduce Monte Carlo (MC) molecular simulation results of the canonical (single-phase) and the NVT-Gibbs (two-phase) ensembles for a system of normalized structureless Lennard-Jones (LJ) particles. The main advantage of such surrogates, once generated, is the capability of accurately computing the needed thermodynamic quantities in a few seconds, thus efficiently replacing the computationally expensive MC molecular simulations. Benefiting from the tremendous computational time reduction, the PC surrogates were used to conduct large-scale optimization in order to propose single-site LJ models for several simple molecules. Experimental data, a set of supercritical isotherms, and part of the two-phase envelope, of several pure components were used for tuning the LJ parameters (ε, σ). Based on the conducted optimization, excellent fit was obtained for different noble gases (Ar, Kr, and Xe) and other small molecules (CH4, N2, and CO). On the other hand, due to the simplicity of the LJ model used, dramatic deviations between simulation and experimental data were observed, especially in the two-phase region, for more complex molecules such as CO2 and C2 H6.
Original languageEnglish (US)
Pages (from-to)214301
JournalThe Journal of Chemical Physics
Issue number21
StatePublished - Jun 2 2016

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: This research is funded by King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.


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