Scattering model for tetrapods with cylindrical arms

Abstract

A scattering model for regular tetrapods, which are the endoskeleton structure of regular tetrahedrons, is presented. Since a tetrapod, unlike spheres and cylinders, is an anisotropic structure formed by four cylinders branching out from the centroid to the vertices of a tetrahedron, additional symmetry elements and random orientation must be accounted for to develop its scattering model. The scattering function of tetrapods was derived from the modification of the scattering model for cylinders and their structural regularity was simplified. Scattering intensity profiles and pair distance distribution functions were obtained by numerical calculation and compared with the experimental data from small angle X-ray measurements of CdSe tetrapod nanocrystals.