The size distribution of particles leads to smearing effects. The scattered intensity reads
<math> I_
Unknown macro: {poly}
(q,x) = \int_0^
Unknown macro: {infty}
G(x,r) I(q,r) dr</math>
where <math> G(x,r)</math> characterizes the distribution function such that <math> \int G( x, r ) dr = 1</math>.