A number of simple pair interaction potentials of the carbon dioxide molecule
are investigated and found to underestimate the magnitude of the second virial
coefficient in the temperature interval 220 K to 448 K by up to 20%. Also the
third virial coefficient is underestimated by these models. A rigid,
polarizable, three-site interaction potential reproduces the experimental
second and third virial coefficients to within a few percent. It is based on
the modified Buckingham exp-6 potential, an anisotropic Axilrod-Teller
correction and Gaussian charge densities on the atomic sites with an inducible
dipole at the center of mass. The electric quadrupole moment, polarizability
and bond distances are set to equal experiment. Density of the fluid at 200 and
800 bars pressure is reproduced to within some percent of observation over the
temperature range 250 K to 310 K. The dimer structure is in passable agreement
with electronically resolved quantum-mechanical calculations in the literature,
as are those of the monohydrated monomer and dimer complexes using the
polarizable GCPM water potential. Qualitative agreement with experiment is also
obtained, when quantum corrections are included, for the relative stability of
the trimer conformations, which is not the case for the pair potentials.Comment: Error in the long-range correction fixed and three-body dispersion
introduced. 32 pages (incl. title page), 7 figures, 9 tables, double-space