The separation of the optical potential for electron-molecule scattering into a local and a non-local part

The physical origin of the different contributions to the optical potentials of the electron-molecule scattering problem is analysed. A method is proposed for separating the optical potential into a local, long-range and energy-independent term and into a non-local, short-range and energy-dependent one. Such a separation is desired if one treats the electron scattering off the local and off the non-local part of the interaction by different numerical methods as recently proposed by several different authors. The separation scheme is applied to the e - +N 2 scattering problem and it is shown that the proposed separation significantly improves the quality of the representation of the interaction.