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A general nonparameterized continuum scattered wave (CMS) method for calculating total and differential elastic cross sections for electron-molecule scattering at low energies (0-30 eV) is presented. The method uses a local exchange approximation based on the Hara free electron gas model. The parameters required for exchange potential and the energy-dependent polarization potential are generated entirely within the calculation. CMS results for argon and methane are presented. The argon results compare very favorably with results recently obtained from an ab-initio R-matrix method. At very low energies the results agree very well with recent experimental work for the scattering length and the position and magnitude of the Ramsauer-Townsend minima observed for both argon and methane. An analysis of the potential suggests that the Slater transition-state half-occupation method used to generate the scattering potential could be a way of automatically including both a self-interaction correction and a weak correlation-polarization term similar to that obtained from the accurate electron gas correlation expression of Ceperly and Alder.

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