Fig. 2. Water dimer interaction energies.

a Smith stationary points⁷³ and b MD simulated water dimers with the oxygen-oxygen distance. For a, MAEs of each functional are (following the order in the legend) 0.25, 0.11, 0.09, 0.17, and 0.08 kcal/mol. DLPNO-CCSD(T)-F12 has been used as a reference. For b, MAE of each functionals are 0.25, 0.08, 0.20, 0.30 and 0.08 kcal/mol. Supplementary Fig. 1 shows the corresponding density sensitivities and Supplementary Fig. 2 shows the errors of approximations for the Smith dimers and interaction energies for MD dimers.