Effective potential methods in variational treatments of electron-molecule collisions. I. Theoretical formulation

We investigate the use of current effective core potentials to simplify variational treatments of electron scattering by target molecules containing one or more heavy atoms. The nonlocal character of these potentials poses severe computational problems for general algebraic variational methods that do not rely on specific analytic schemes for computing matrix elements. We show that standard l-dependent pseudopotentials can be represented in a way that facilitates the numerical evaluation of the required collision integrals.