Asymmetry in elastic scattering of polarised electrons by optically active molecules

Elastic scattering of polarised electrons by optically active molecules is treated on the basis of such a simplified muffin-tin model that a molecule consists only of non-overlapping spheres with spin-orbit interaction incorporated. The scattering problem is solved with the approach presented in an earlier paper, and only the lowest-order partial spin-flip amplitudes are taken into account. Asymmetry in scattering phenomena is described by in-plane components of the function W( theta ) which is defined in terms of (a) direct and spin-flip partial scattering amplitudes for constituent atoms and (b) a geometrical factor which has the opposite sign for D and L isomers. Preliminary numerical calculations are carried out for an imaginary chiral molecule whose shape is a regular tetrahedron. A shape resonance enhancement of asymmetry is simulated by a simplistic calculation in which the direct-scattering amplitudes are so determined that the cross section can exhibit a resonance peak. The asymmetry in attenuation and the rotation of transverse polarisation are found to peak at energies different from the resonance energy.