Optimized Gaussian basis sets for representation of continuum wavefunctions

Exponents of Gaussian-type basis functions have been optimized for electron-molecule scattering purposes. The criterion for optimization was to obtain the best least-squares fit to six Bessel functions j_l(k_h^(l)*r) representing the continuum functions. The values for the radial momentum k_h^(l) are defined by the boundary conditions for the Bessel functions to have vanishing radial derivatives at r=20 au. For each l=0, 1 and 2, Gaussian basis sets of eight functions have been optimized. The results are of excellent quality. It is therefore concluded that usual atomic Gaussian basis sets, augmented by these functions, can be sufficient in electron-molecule scattering calculations, such as R-matrix calculations, for example.