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 and Yamaguchi. 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 eigenvalue method. 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. (orig.)