Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, USA.
J Phys Chem B. 2011 May 5;115(17):4949-54. doi: 10.1021/jp2010524. Epub 2011 Apr 8.
A new force field for sulfur dioxide, capable of predicting accurately the vapor-liquid equilibria, critical properties, vapor pressure, and heats of vaporization is presented. The new force field reproduces the saturated liquid densities, vapor pressures and heats of vaporization to within 0.5, 2, and 2% of experiment, respectively. The predicted critical properties and the normal boiling point are in excellent agreement with experimental results. Pair distribution functions are calculated for the S-S, S-O, and O-O interactions are in close agreement with neutron and X-ray scattering experiments. In addition to the new force field, similar calculations are performed for four SO(2) intermolecular potentials proposed by Sokolic et al. (Sokolic, F.; Guissani, Y. and Guillot, B. J. Phys. Chem. 1985, 89, 3023], which show that these models work reasonably well near the state point where they were originally parametrized, but large errors in the predicted coexistence properties are displayed at higher and lower temperatures. Comparison of the radial distribution functions show the local structure is only weakly affected by the different force field parameters.
提出了一种新的二氧化硫力场，能够准确预测汽液平衡、临界性质、蒸气压和蒸发热。新力场分别将饱和液体密度、蒸气压和蒸发热的实验值再现到 0.5、2 和 2%以内。预测的临界性质和正常沸点与实验结果非常吻合。计算了 S-S、S-O 和 O-O 相互作用的配分函数，与中子和 X 射线散射实验非常吻合。除了新的力场外，还对 Sokolic 等人提出的四个 SO(2)分子间势能进行了类似的计算（Sokolic，F.；Guissani，Y.和Guillot，B. J. Phys. Chem. 1985，89，3023），结果表明这些模型在最初参数化的状态点附近工作得相当好，但在更高和更低的温度下，预测的共存性质会出现较大误差。比较径向分布函数表明，不同力场参数仅对局部结构产生微弱影响。
