Small-angle scattering with azimuthal asymmetry

Small-angle scattering spectra which lack azimuthal symmetry indicate structural anisotropy. For data which exhibit elliptical azimuthal symmetry, the system under investigation has generally been modelled by aligned rotational ellipsoids for the inhomogeneities. It is shown that the scattering centers do not necessarily have to be ellipsoidal, but only that they have azimuthal symmetry around some unique axis within the sample. The scattered intensity may then be described by an ellipsoidal function. The Guinier approximation can also be made for inhomogeneities with only azimuthal symmetry.