KENBIKYO Vol.50▶No.1 2015
â– Feature Articles: Fundamentals of Simulation for Electron Microscopy

Geometry of Electron Diffraction and Its Calculation

Toshihiro Kogure

Abstract: Geometrical calculation and drawing of electron diffraction patterns using computers are described according to the reciprocal lattice, Ewald construction and extinction rule. Reciprocal lattice points with the excitation error less than a set value are plotted, including those in high-order Laue zones. A procedure to determine the incident beam direction and indices of the reflections for experimental diffraction patterns is also introduced. The distances between three reflections in the zero-order Laue zone are used to find the candidates of the indices for the reflections and they were examined by the comparison between the experimental and calculated diffraction patterns.

Key words: electron diffraction, reciprocal lattice, Ewald construction, forbidden reflections, computer program