Molecular Dynamics Simulation of Liquid Alkanes. I. Thermodynamics and Structures of Normal Alkanes : n-butane to n-heptadecane

摘要: We present results of molecular dynamic (MD) simulations for the thermodynamic and structural properties liquid n-alkanes, from n-butane to n-heptadecane, using three different models Ⅰ-Ⅲ. Two classes are collapsed atomic while third class is an atomistically detailed model. Model Ⅰ original Ryckaert Bellemans' model [Discuss. Faraday Soc. 1978, 66, 95] Ⅱ expanded which includes C-C bond stretching C-C-C angle bending potentials in addition Lennard-Jones torsional Ⅰ. In Ⅲ all carbon hydrogen atoms monomeric units represented explicitly alkane molecules. Excellent agreement our MD with those Edberg et al.[J. Chem. Phys. 1986, 84, 6933], who used a algorithm confirms validity algorithms 14 n-alkanes n-butane, n-decane, n-heptadecane. The very similar each other not much Ⅱ. However, as observed by comparing radial distribution functions, average end-to-end distances root-mean-squared radii gyrations.