An accurate determination of the HeAr van der Waals potential

A new van der Waals potential for HeAr is constructed from a systematic analysis of differential cross section scattering data. The significant discrepancies between this potential and those based on similar experiments in other laboratories are shown to be due primarily to biases present in the mathematical parameterizations used previously. The new potential is valid for interatomic separations between 2.4 Å and 6.5 Å, and provides an excellent description of all available HeAr data, including transport and virial coefficients. This potential, which has a well depth of 1.78 meV, is parameterization-independent and accurate to 10%.