Guinier approximation
= Guinier approximation
{c}
{title2=$I(q)\simeq I(0)e^{-q^2R_g^2/3}$}
The low-wave-number approximation relating the scattering form factor of an isotropic dilute population to its <radius of gyration>. Fitting its range requires $qR_g$ sufficiently small and negligible or corrected interparticle scattering.