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The nonbonding interaction energies of carbon dioxide dimer were calculated using several basis sets to evaluate the basis set effects. Large basis sets including multiple polarized functions were necessary to evaluate the interaction energies correctly. Small basis sets considerably underestimated the interaction energies. Nonbonding parameters of a model potential of carbon dioxide were refined based on the intermolecular interaction energies of 40 geometrical configurations of dimers calculated by an MP2/6-311+G(2df)-level ab initio method with the basis set superposition error (BSSE) correction. The molar volume and heat of evaporation of liquid carbon dioxide obtained from molecular dynamics simulations with the model potential reproduced the experimental values with an error of only a few percent. On the other hand, the model potential based on the BSSE-uncorrected interaction energies overestimated the attractive interaction and failed to reproduce the experimental values. The structure and lattice vibrational frequencies of carbon dioxide molecular crystal in the low-pressure phase (1 atm) and the structure in the high-pressure phase (20 GPa) were also well reproduced by the same model potential proposed here.
