To compare the predictions of the RR-cpH algorithm with the canonical titration method, we consider a colloidal particle of radius of 60 Å and Z = 600 surface groups. Simulations are carried out within a cubic box of side lengths L, containing a colloidal particle at its center. Ewald summation is used to account for Coulomb interactions. In the spirit of coarse grained RR-cpH algorithm, we use the primitive model of solvent that treats water as a uniform dielectric continuum of Bjerrum length λ B = q 2 /(k B T w ) = 7.2 Å. Active functional groups have intrinsic pK a = 5.4. The simulation cell also contains ions H 3 O + , Cl -, and Na + , which we all treat as hard spheres of radius 2 Å with a point charge located at the center.