The test set contains 4 unique protein complexes with 6 distinct protein folds that display a diverse mix of secondary structure content in the solution proteins UBA domain/Ubiquitin and Barnase/Barstar, and almost completely beta structure in the OMPLA homodimer (transmembrane beta-barrel) or only helical structure in the ClC homodimer (transmembrane helix bundle). The rationale behind choosing protein complexes as test systems is that it allows us to obtain more reference sampling with two proteins in each system while also assessing their interface contact stability and thus whether there is a need for stabilizing quaternary structure further in the coarse-grained simulations. The protein interfaces show various interactions that range from being predominantly hydrophobic (UBA domain/Ubiquitin, SI Figure & ClC homodimer, SI Figure ) and a system containing polar and hydrogen bonding residues (OMPLA homodimer, SI Figure ) and also a system with a large fraction of charged residues (Barnase/Barstar, SI Figure ).