The solvent accessible surface area (SASA) of a dom-face is calculated as the sum of the total decreased SASA for the interface atoms in a domain, see Equation 1. If A and B are two protomers in the complex AB, SASAA, SASAB and SASAAB are SASA values for A, B, and AB respectively, and n is the total number of interface atoms in a domain presented in protomers A and B, then