Figure 1.

Modelling the shape function for a cube of edge length ∼16 nm. The shape function, , is computed by summing the CVFs, , over a set of directions. Here the CVFs for the [100], [110] and [111] directions are shown as an example. The contribution for each direction was scaled with the area fraction, , of a unit-surface-area sphere divided by a tessellation for which the projections of the directions are generator centres (schematic inset). The small-angle PDF correction in equation (6) was then computed assuming , i.e. by ignoring material composition.