TABLE 2.

Average adjacent O-O distance (${\overline{R}}_{O-O}$) and the average Ca-O distance between Ca²⁺ and oxygen atoms in the first (${\overline{R}}_{Ca-O}^1$), second (${\overline{R}}_{Ca-O}^2$), and third (${\overline{R}}_{Ca-O}^3$) shell water molecules of the lowest-energy structures of Ca²⁺(H₂O)_10–18 clusters.

n	${\overline{R}}_{O-O}\AA$	${\overline{R}}_{Ca-O}^1\AA$	${\overline{R}}_{Ca-O}^2\AA$	${\overline{R}}_{Ca-O}^3\AA$
10	2.818	2.385	4.257	—
11	2.825	2.381	4.275	—
12	2.839	2.380	4.281	—
13	2.852	2.426	4.350	—
14	2.822	2.477	4.528	—
15	2.843	2.425	4.411	6.149
16	2.791	2.446	4.169	5.005
17	2.775	2.518	4.083	—
18	2.781	2.521	4.106	—