Table 2. Optimized surface energy, γ, and ∂ln(p/p ₀)/∂T in the TLDM for 133 K using ΔH _n,n–1 values for clusters with 20–500 water molecules and compared to bulk parameters. The RMSD between of experiment and theory is given in kJ mol^–1. For divalent ions the results in parentheses indicate the fit without Fe²⁺/Mn²⁺ ions.

Charge	γ/mN m–1	∂ln(p/p 0)/∂T/10–2 K–1	RMSD/kJ mol–1
1+	182 ± 23	34.3 ± 0.7	0.92
2+	215 ± 26 (180 ± 27)	35.5 ± 0.8 (34.1 ± 0.8)	1.17 (0.84)
3+	269 ± 17	36.4 ± 0.5	0.67
Bulk	109 a	31.8 b	—

^a ref. 69.

^b ref. 49.