Figure 2.

Illustration of the two main stages of the algorithm. (a) First stage: finding a set of possible directions (shown here by arrows) for a given set of reflections (here blue points A through F) and selecting the ‘best’ one(s) to consider at the second stage. Among the ten directions found for the set of points A, B, C, D, E, F, the ‘best’ one (shown by the green arrow) is identified as that corresponding to the largest number of collinear vectors. (b) The second stage: finding the ‘proper’ distance between the reflections (here denoted as ‘d’) in the selected direction. (c) An example of a view of the reciprocal space with the subset of points (orange dots) found in the initial set (blue dots).