A Set of Molecular Models for Symmetric Quadrupolar Fluids

Molecular models for 25 different pure fluids are presented: neon, argon, krypton, xenon, methane, oxygen, nitrogen, fluorine, chlorine, bromine, iodine, carbon dioxide, carbon disulfide, ethane, ethene, ethyne, perfluoroethane, perfluoroethene, perchloroethene, propadiene, propyne, sulfurhexafluoride, tetrafluoromethane, tetrachloromethane, and propylene. The models are based on the two-center Lennard-Jones plus pointquadrupole pair potential (2CLJQ). The model parameters were adjusted to experimental vapor-liquid equilibria of the pure fluids using a highly efficient procedure. The application of these models to the calculation of vapor-liquid equilibria and homogeneous fluid state points by molecular simulation shows good agreement with experimental results. Numbers for model parameters correlate reasonably with geometric data of the molecules and experimental quadrupole moments. Due to the compatibility of the presented models, applications to the prediction of vapor-liquid equilibria of mixtures are straightforward.