Scattering from a Crystal Lattice

From this one can see that the perpendicular distance between the b-c planes on adjacent unit cells along a is the reciprocal of a. We can denote the stack of these b-c planes by their respective intercepts on the abc triplet of real space axes as (a/1, b/0, c/0), or simply (100). Similarly, another stack of planes can be constructed by selection of reciprocal integer intercepts (a//z, b/k, cjl) and denote them with just the denominators hkt). These are the Miller indices for this stack of planes they correspond to a lattice point in reciprocal space coincident with the vector h which has an associated structure factor Fy, as defined in Equation (15). Because of the connection between the real and reciprocal lattices, the vector h is perpendicular to its respective stack of planes and the interplanar spacing is the reciprocal of the magnitude of h this is the (i-spacing for these planes. 

The scattered intensity Bragg scattering) from a small single erystal is determined by the interference between the individual scattering centers that make up the crystal structure  

---