In Eq. 2, the peak function and bkg are analogous to those in Eq. 1, and erf is an error function. On the other hand, the SAXS part of the data (analogous to regions I and III in Fig. ) is no longer following only a pure surface-fractal-like I(q) ~ q -A decline, and Rs parameter is a radius of gyration of a structural "building block". It is assumed that this building block is sphere-like for Ps = 4. The surface fractal contribution is still present, where the characteristic scaling exponent is P. Finally, Gs, Bs, and B are scaling constants. For Rs = 0 (i.e. in the absence of defined building blocks), the unified model component becomes the surface fractal component from Eq. 1, where P = 6 -Ds and B is a perfector expression preceding q -6 + D in Eq. 1. The Orenstein-Zernike heterogeneity term was omitted because its contribution overlaps with those of the unified function (the Bs), which leads to overparameterization. In Fig. we show the fit to the data with Eq. 2 and the minimized parameters are reported in the figure caption.