Abstract
A new interatomic potential for helium is proposed of the form: with a=0·675 å, α=4·390 å -1, β=3·746 × 10-4 å -6 and A=398·7 ev. The long-range attraction has the correct theoretical dependence on the separation with the terms having the coefficients as calculated by Dalgarno and Kingston and by Davison. The short-range repulsive part of the potential was fitted to the calculated potential energy values of Phillipson and the experimentally determined values of Amdur and his co-workers. In addition the parameters were adjusted so that the potential reproduces the experimentally determined second virial coefficient for helium.