Quantitative CBED: an overview
In this abstract I will focus on one particular topic which has widespread relevance in the quantitative analysis of CBED; namely the role of computer simulations of CBED patterns. The basic point is that with modern, high-powered workstations we can perform highly accurate and detailed simulations of all types of CBED patterns from crystals in a relatively short amount of time. Most CBED simulations are based on diagonalisation of the many-beam equations, and, for example, on a DEC Alpha workstation one can perform this calculation on a 150 × 150 matrix (sufficient for a highly accurate simulation in many systems) in around 1.8s. A full, two-dimensional CBED pattern with, say, 50 orientations across each disc (which is a high-resolution simulation) can then be calculated in less than 1 hour. How can such simulations be used in a quantitative analysis of CBED patterns? I will address this by looking at some specific examples covering various aspects of quantitative CBED.