Ab initio calculations of thermophysical properties of gaseous and super critical fluids over a wide range of temperature and density

在气态和超临界区域内，根据从头算势能，可以高精度地计算具有科学和工业意义的流体的热物理性质。被调查的流体是环氧乙烷、一氧化二氮、硫化氢和甲烷。第二到第七维里系数将使用有效的蒙特卡罗方法来确定。此外，还利用气体动力学理论计算了低密度下的输运性质。对于甲烷和硫化氢，提供了该对相互作用所需的高精度势函数。对于环氧乙烷和一氧化二氮，它们将根据量子化学从头计算方法进行计算。第三到第七维里系数受非加性多体相互作用的影响，这些多体相互作用将以非加性三体势的形式来考虑。必须使用从头算方法计算所有四种物质的这些势。热物性的计算值应该有很高的精度，否则只能用最好的实验方法才能得到。

Thermophysical properties of scientifically and industrially important fluids are to be calculated with high accuracy in the gaseous and supercritical region on the basis of ab initio potentials. The fluids to be investigated are ethylene oxide, nitrous oxide, hydrogen sulfide and methane. The second to seventh virial coefficients are to be determined using efficient Monte Carlo methods. In addition, the transport properties at low densities are to be calculated utilizing the kinetic theory of gases. The required highly accurate potential functions for the pair interactions are available for methane and hydrogen sulfide. For ethylene oxide and nitrous oxide they are to be computed on the basis of quantum-chemical ab initio methods. The third to seventh virial coefficients are affected by nonadditive many-body interactions, which are to be considered in the form of nonadditive three-body potentials. These potentials have to be calculated for all four substances using ab initio methods. The calculated values of the thermophysical properties should be of very high accuracy which can otherwise only be achieved with the best experimental methods.