title: Fully atomistic molecular-mechanical model of liquid alkane oils: Computational validation.
abstract: Fully atomistic molecular dynamics simulations were performed on liquid n-pentane, n-hexane, and n-heptane to derive an atomistic model for middle-chain-length alkanes. All simulations were based on existing molecular-mechanical parameters for alkanes. The computational protocol was optimized, for example, in terms of thermo- and barostat, to reproduce properly the properties of the liquids. The model was validated by comparison of thermal, structural, and dynamic properties of the normal alkane liquids to experimental data. Two different combinations of temperature and pressure coupling algorithms were tested. A simple differential approach was applied to evaluate fluctuation-related properties with sufficient accuracy. Analysis of the data reveals a satisfactory representation of the hydrophobic systems behavior. Thermodynamic parameters are close to the experimental values and exhibit correct temperature dependence. The observed intramolecular geometry corresponds to extended conformations domination, whereas the intermolecular structure demonstrates all characteristics of liquid systems. Cavity size distribution function was calculated from coordinates analysis and was applied to study the solubility of gases in hexane and heptane oils. This study provides a platform for further in-depth research on hydrophobic solutions and multicomponent systems.
authors.affiliation: Department of Physical Chemistry, University of Sofia, Faculty of Chemistry and Pharmacy, 1 James Bourchier blvd., 1164, Sofia, Bulgaria.
authors.forename: Tsvetan K
authors.initials: TK
authors.lastname: Zahariev
authors.affiliation: Department of Physical Chemistry, University of Sofia, Faculty of Chemistry and Pharmacy, 1 James Bourchier blvd., 1164, Sofia, Bulgaria.
authors.forename: Radomir I
authors.initials: RI
authors.lastname: Slavchov
authors.affiliation: Department of Physical Chemistry, University of Sofia, Faculty of Chemistry and Pharmacy, 1 James Bourchier blvd., 1164, Sofia, Bulgaria.
authors.forename: Alia V
authors.initials: AV
authors.lastname: Tadjer
authors.affiliation: Department of Physical Chemistry, University of Sofia, Faculty of Chemistry and Pharmacy, 1 James Bourchier blvd., 1164, Sofia, Bulgaria.
authors.forename: Anela N
authors.initials: AN
authors.lastname: Ivanova
keywords: cavities distribution; liquid structure; molecular dynamics simulations; n‐alkane oils; thermodynamic properties; transport coefficients