Transferable Step Potentials for the Straight-Chain Alkanes, Alkenes, Alkynes, Ethers, and Alcohols

Discontinuous molecular dynamics simulation and thermodynamic perturbation theory have been used to study thermodynamic and transport properties for hydrocarbons and oxygenated compounds. The fundamental basis of the method relies on a stepwise characterization of the disperse interactions and Wertheim potentials for the hydrogen bonding. The study on the transferable step potential energies, which are used to correlate the physical properties, the vapor pressure and liquid density, from available experimental data in the literature for straight-chain alkanes is extended to straight-chain alkenes, alkynes, ethers, and alcohols. The transferable multistep potentials for the new training set of pseudo-atoms governed by two transferable square-well depths and diameters are introduced, being transferable for the selected model compounds in each family. Those transferable parameters are applied to a set of validation compounds, and the results are analyzed. Overall, the vapor pressures and liquid densities are correlated to within 5% error with reduced temperatures extending to 0.45 for n-alkanes, alkenes, alkynes, ethers, and alcohols while applying transferable characterizations of the individual pseudo-atoms' molecular interaction potentials.