Figure 2
(Left) Part of a hypothetical one-dimensional unit cell corresponding to an atomic position, with schematic representation of the associated δM(x) and ρ(x) [equation (5)]. The binary mask mΔδ(x) is 1 if δM(x) is larger than the Δδ threshold and 0 otherwise. (Right) The same part of the unit cell shows the product function δM(x)mΔδ(x), which is proportional to ρ(x) (for equiatomic structures). If the number N of expected atoms in the unit cell is known, then the δM tangent formula reduces to a structure factor calculation over the N largest product-function peaks greater than Δδ, i.e. the integral of the FT in expression (7) reduces to a sum. |