The lattice distortion theory of Zele and co-workers is an attractive method for amending calculated phase equilibria of clathrate hydrates, since only two molecular computations are required. The perturbation energy between the empty and loaded clathrate hydrate lattice is the quantity of interest. The effect of binary correction factors applied to the Lorentz and Berthelot com- bining rules for the intermolecular interaction between gas and water particles is investigated. There are clear trends for the perturbation energy and lattice constant in terms of the binary correction factors, although there is signi fi cant sensitivity to the force fi eld parameterization of the gas species.