On the other hand, the theory predicts that μ μ does depend on temperature. For rigid elastic spheres, the predicted scaling is μ μ ∝ ∝ T 1 / 2 , while other models typically show greater variation with temperature. For instance, for molecules repelling each other with force ∝ ∝ r − − ν ν the predicted scaling is μ μ ∝ ∝ T s , where s = 1 / 2 + 2 / ( ν ν − − 1 ) . Taking s = 0.668 , corresponding to ν ν ≈ ≈ 12.9 , shows reasonable agreement with the experimentally observed scaling for helium. For more complex gases the agreement is not as good, most likely due to the neglect of attractive forces. Indeed, the Lennard-Jones model, which does incorporate attractions, can be brought into closer agreement with experiment (albeit at the cost of a more opaque T dependence; see the Lennard-Jones entry in table 1). For better agreement with experimental data than that which has been obtained using the Lennard-Jones model, the more flexible Mie potential has been used, the added flexibility of this potential allows for accurate prediction of the transport properties of mixtures of a variety of spherically symmetric molecules.