Table 4. Comparison of Calculated and Observed Solvation Free Energies (ΔGhyd, kcal/mol), and Ion–Water Oxygen Distances (M2+–O, Å) Using Our Parameter Set from Table 1 for Different Metalsa,b.
TIP3P |
SPC |
experimental |
||||
---|---|---|---|---|---|---|
ΔGhyd | M2+–O | ΔGhyd | M2+–O | ΔGhyd54 | M2+–O52 | |
Fe | –451.9 ± 0.2 | 2.13 ± 0.04 | –450.0 ± 0.1 | 2.14 ± 0.04 | –451.8 | 2.12 |
Ni | –492.7 ± 0.1 | 2.06 ± 0.03 | –490.8 ± 0.2 | 2.07 ± 0.03 | –492.8 | 2.06 |
Co | –480.5 ± 0.1 | 2.08 ± 0.03 | –478.7 ± 0.2 | 2.09 ± 0.03 | –481.0 | 2.08 |
Zn | –483.4 ± 0.1 | 2.08 ± 0.03 | –481.4 ± 0.2 | 2.09 ± 0.03 | –483.3 | 2.08 |
Mn | –436.9 ± 0.2 | 2.19 ± 0.03 | –433.1 ± 0.1 | 2.20 ± 0.04 | –436.4 | 2.20 |
Mg | –454.4 ± 0.1 | 2.12 ± 0.04 | –452.3 ± 0.1 | 2.13 ± 0.04 | –454.2 | 2.10 |
Ca | –379.9 ± 0.2 | 2.38 ± 0.02 | –377.9 ± 0.2 | 2.39 ± 0.01 | –379.5 | 2.39–2.4676,77 |
All 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).