Inspired by this work, we developed a rigorous scheme to estimate the onset of entropy in dissociation reactions by addressing the previous issues. We assumed that 50% of the final entropy is reached once the bond is broken and deduced the bond cleavage distance from analysis of chemical descriptors, such as bond order indices, which were calculated along the reaction path. This distance was set as the inflection point of our sigmoid-shaped entropy fit function. The steepness of the function was determined by adjusting a parameter k, while assuming that there is no energy minimum after the inflection point. We developed our methodology at the example of the water dimer, testing a set of quantum chemical descriptors in combination with various basis set and density functionals and benchmarked against experimental data. Comparison with VTST data for the C 2 F 4 dimer, showed excellent agreement of our method, while applicability to large inorganic complexes has also been demonstrated.