Paper Citing NAMD - Abstract
Kamath, Ganesh; Ketko, MaryBeth; Baker, Gary A.; Potoff, Jeffrey J.
Monte Carlo predictions of phase equilibria and structure for dimethyl ether plus sulfur dioxide and dimethyl ether plus carbon dioxide
JOURNAL OF CHEMICAL PHYSICS, 136 Art. No. 044514, JAN 28 2012
A new force field for dimethyl ether (DME) based on the Lennard-Jones (LJ) 12-6 plus point charge functional form is presented in this work. This force field reproduces experimental saturated liquid and vapor densities, vapor pressures, heats of vaporization, and critical properties to within the statistical uncertainty of the combined experimental and simulation measurements for temperatures between the normal boiling and critical point. Critical parameters and normal boiling point are predicted to within 0.1% of experiment. This force field is used in grand canonical histogram reweighting Monte Carlo simulations to predict the pressure composition diagrams for the binary mixtures DME + SO2 at 363.15 K and DME + CO2 at 335.15 and 308.15 K. For the DME + SO2 mixture, simulation is able to qualitatively reproduce the minimum pressure azeotropy observed experimentally for this mixture, but quantitative errors exist, suggesting that multibody effects may be important in this system. For the DME + CO2 mixture, simulation is able to predict the pressure-composition behavior within 1% of experimental data. Simulations in the isobaric-isothermal ensemble are used to determine the microstructure of DME + SO2 and DME + CO2 mixtures. The DME + SO2 shows weak pairing between DME and SO2 molecules, while no specific pairing or aggregation is observed for mixtures of DME + CO2. (C) 2012 American Institute of Physics. [doi:10.1063/1.3677880]
