Before revision:  Third, KiNetX estimates the sensitivity of species concentrations toward changes in individual activation free energies , which allows us to systematically select the most efficient quantum chemical model for each elementary reaction given a predefined accuracy.
After revision:  Third, KiNetX estimates the sensitivity of species concentrations toward changes in individual rate constants (derived from relative free energies) , which allows us to systematically select the most efficient quantum chemical model for each elementary reaction given a predefined accuracy.