Table 3. Comparison of Calculated and Observed Solvation Free Energies (ΔG_hyd, kcal/mol), and Ion–Water Oxygen Distances (M²⁺–O, Å) Employing Parameters Developed by Åqvist and Warshel^17,32 for Mn²⁺ and Zn²⁺ Dummy Models, by Oelschlaeger et al.³¹ for Mg²⁺ Dummy Model, and by Saxena and Sept³⁹ for Ca²⁺ Dummy Model. For Comparison, the Results Using Soft-sphere Models are also Presented in Table S1.^a.

								TIP3P		experimental
	e	AiM	BiM	mM	AiD	BiD	mD	ΔGhyd	M2+–Oa	ΔGhyd54	M2+–O52
Mnb	–0.1	145	25.0	48.94	0.00	0.00	1.0	–440.9 ± 0.1	2.14 ± 0.05	–436.4	2.20
Znb	–1.0	136	41.0	59.38	0.00	0.00	1.0	–479.5 ± 0.1	2.07 ± 0.04	–483.3	2.08
Mgc	–1.0	70.0	41.0	6.3	0.05	0.00	3.0	–484.9 ± 0.1	2.08 ± 0.03	–454.2	2.10
Cad	0.0	233.2	35.5	33.1	0.05	0.00	1.0	–408.6 ± 0.2	2.32 ± 0.02	–379.5	2.39–2.4676,77

^aAll values are averages and standard deviations over five trajectories, as outlined in the main text. M–O distances for all of the water molecules bound to the metal were monitored along the simulation. Only for calcium, which shows a rapid water exchange, the M–O distance was directly taken from the peak of the RDF (see Supporting Information Figure S1).

^bK_b = 1600 (kcal mol⁻¹Å⁻²) and K_θ = 250 (kcal mol⁻¹rad⁻²) and no bond between dummies.

^cK_b = 640 (kcal mol⁻¹Å⁻²) and K_θ = 55 (kcal mol⁻¹rad⁻²).

^dK_b = 540 (mol⁻¹Å⁻²) and K_θ =55 (kcal mol⁻¹rad⁻²) and no bond between dummies.