Molecular Dynamics Simulations of Liquid Nitromethane

• Published in: The journal of physical chemistry. B 1999-11, Vol.103 (44), p.9738-9742
• Main Authors: Alper, Howard E, Abu-Awwad, Fakhr, Politzer, Peter
• Format: Article
• Language: English
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp9921102

A potential energy function with harmonic intramolecular and Lennard-Jones plus Coulombic intermolecular terms was tested in molecular dynamics simulations of liquid nitromethane. Parameter values were adjusted iteratively until satisfactory agreement with density functional pair calculations and experimental data was achieved. The properties computed using the NVT and NPT ensembles were the heat of vaporization, dielectric constant, self-diffusion coefficient, density, heat capacity at constant pressure, pair correlation functions, single molecule and collective dipole moment reorientation times, the vibrational spectrum, and the effect of increasing pressure upon the C−N stretching frequency. Overall, the results were in reasonable accord with experimental results, the greatest discrepancy being for the dielectric constant. It was concluded, on the basis of the reorientation times and the calculated molecular surface electrostatic potential, that the intermolecular interactions in liquid nitromethane at 1 atm are not highly directional and site-specific.