A new approach for n-beam dynamical calculations

With the use of modulated plane waves, a new method for n-beam dynamical calculations has been established on the basis of a paper by Watanabe, Kikuchi, Hiratsuka & Yamaguchi [Phys. Status Solidi A (1988), 109, 119-126]. The computing time is reduced to about one-sixth of what it originally was and a large reduction of memory is achieved, n-beam dynamical calculations of aluminium, copper and gold at several accelerating voltages and orientations were carried out in a completely parallel manner by the present method, the multi-slice method and Bethe's eigen-value method [Fujiwara (1959). J. Phys. Soc. Jpn 14, 1513-1524]. The present method turned out to be competitive with respect to accuracy and speed in comparison with the latter two methods. The new method makes n-beam dynamical calculations of complex systems and defects possible.