where 𝜆 is a regularization term, 𝑘 liq,expt is an experimental rate constant, and 𝑘 liq,calc is a calculated rate constant which is a function of the kinetic parameters to be optimized. The regularization term is added in eq 17 to prevent the solvation parameters (ΔΔ𝐺 ‡ solv (298 K), ΔΔ𝐻 ‡ solv (298 K)) from being overfitted to the experimental data. The optimal value of 𝜆 is identified as 0.0001 when a kcal/mol unit is used for the solvation parameters in the loss function. Only the solvation parameters are regularized as their values typically fall within ±7 kcal/mol for most reactions and larger values are rare unless the polarity of the TS is significantly different from that of the reactants . We also found that adding the regularization term for the solvation parameters provides more reasonable results for the optimized kinetic parameters.