The titration isotherm calculated using this procedure is presented in Fig. . As a benchmark to check the accuracy of the new canonical titration method, we compared our results with the ones calculated using rGCMCD simulation . We see a perfect agreement between the two methods. We have then repeated the calculation for a system with 50mM of salt. Again the agreement between the two simulation methods is excellent, see Fig. The solid green curve is the benchmark calculated using rGCMCD simulation method of ref. . The solid green curve is the benchmark calculated using rGCMCD simulation method of ref. .