Python script fit-experiment developed for WAXSiS allows fitting of experimental SAS intensity curves to modelled (calculated/simulated) intensity curves.

fit-experiment

The Weighted Histogram Analysis Method (WHAM) is a standard technique used to compute potentials of mean force (PMFs) from a set of umbrella sampling simulations.

We have written a GROMACS extension that allows you to apply a harmonic (or umbrella-like) restraint along the radius of gyration $R_g$ of a group of atoms (typically molecule).