Morse potential parameterization for Ar (quintic smoothing). The low-temperature limits of the thermal expansivity, specific heat, and Grüneisen parameter of solid argon, krypton, and xenon are calculated from a quasiharmonic two-body central-force model. The form of our interatomic potential and its predicted thermal and elastic properties are in good agreement with interatomic potentials for argon and krypton derived from solid-state properties plus gas viscosities, second-virial coefficients, and molecular-beam scattering data.