Simulations of rare-gas gaseous mixtures taking ternary interactions into account are performed. Simulations include Ne-Ar-Kr at 300 K and He-Ar, with Ar in excess, at 165 K. The He-Ar mixtures, which were studied in more detail, give rise to a collision-induced absorption spectrum with a well-formed dip at zero frequency. The dip becomes discernible at a Ar density of 132 amagat when the ternary contribution to the zeroth moment amounts to only 2%. Interactions are assumed to be pairwise-additive.