Cubic‐grid Gaussian basis sets for electron scattering calculations. I. Definition and construction

We propose a new type of Gaussian basis sets for use in calculations of electron scattering by molecules. Instead of locating the basis‐set functions on the atomic centers of the target molecule, we place primitive s ‐type Gaussians at the positions of a cubic lattice with a regular grid. The grid and the Gaussian exponent are fixed so as to give the best representation of the plane‐wave function. Plane‐wave functions and Green functions obtained by means of the cubic‐grid basis set are tested graphically against exact functions and functions expressed by means of a conventional Gaussian basis set.