In addition to generating conformational ensembles, hySAS can also be used to refine single structures to enhance the consistency with experimental SAS data. As an example of the latter application, we choose to improve a model of a previously published protein-RNA complex (). This system consists of the 199-residue unwinding protein 1 (UP1) interacting with a 12-mer single strand derived from the primary transcript of the 18a microRNA. The complex was originally refined using metainference, SAXS and NMR data as restraints and successively tested with hySAXS and the Martini bead form factors . Here, we repeated the latter test using the same input files and data but the 1B/3B mapping to compute the forward models. We generated a short trajectory with and without SLC with a value of 0.12 and a SC of 0.8 nm 2 . From each trajectory we obtained a refined structure with a chi-squared of 1 with respect to the SAXS data (Figure ). As for the GSN, to verify our method, we compared the intensities computed from the two selected conformations with the corresponding intensities recalculated with the WAXSiS webserver. We obtained a RMSE of 6.4⋅10 -2 between the PLUMED and the WAXSiS logarithm of the intensities (Figure , left panel) when using the conformation generated without employing the hydration layer correction.