Model2SAS: software for small-angle scattering data calculation from custom shapes

To meet the challenges in resolving the complex morphologies of emergent nanoparticles, a program with a user-friendly graphical user interface has been developed for calculating small-angle scattering curves from custom shapes. The software allows STL-format 3D models, models defined by mathematical functions or combinations of the two as initial input. As a transitional stage, lattice models are generated and the orientation-averaged small-angle scattering data can be calculated using typical spherical harmonics expansion. The validity of the protocol is verified by demonstration models with Protein Data Bank structures and known scattering functions. The software is applied to successfully calculate the scattering curves of a porous spherical shell model where traditional mathematical derivation fails.