The occupancies of the shells of expanded clusters are shown below. The radii are given from the center of a modeled super-cluster (thirteen complete but overlapping icosahedra; 6½ ˣ 280 =1820 water molecules) to the center of the outermost oxygen atoms. The number of water molecules and interstitial cavities are given, together with the percentage of singly (n1), doubly (n2), trebly (n3), and tetra (n4) hydrogen-bonded water molecules, assuming that no outer water molecules are further hydrogen-bonded. On this basis, the second last column gives the percentage hydrogen-bonding (100% = each water molecule has a share in four hydrogen bonds) within the cluster (see Graph below). The number of
H–bonds/H2O give an indication of the enthalpic stability/H2O of the cluster, with the entropic stability inversely indicated by the number of water molecules present. The larger clusters therefore become relatively more stable at lower temperatures and higher enthalpic stability per H2O molecule.
Shell | Radius nm |
Water molecules |
Cavities | % n1 | % n2 | % n3 | % n4 | % H-bonds |
H-bonds /H2O |
---|---|---|---|---|---|---|---|---|---|
0.00 | 1 | ||||||||
1 | 0.38 | 20 | 0 | 0 | 100 | 0 | 75.0 | 1.50 | |
0.54 | 12 | ||||||||
2 | 0.66 | 20 | 50 | 0 | 0 | 50 | 62.5 | 1.25 | |
3 | 0.80 | 60 | 0 | 0 | 60 | 40 | 85.0 | 1.70 | |
0.97 | 12 | ||||||||
4 | 1.07 | 60 | 38 | 0 | 0 | 63 | 71.9 | 1.44 | |
5 | 1.14 | 60 | 0 | 0 | 55 | 45 | 86.4 | 1.73 | |
6 | 1.23 | 60 | 0 | 0 | 43 | 57 | 89.3 | 1.79 | |
1.35 | 60 | ||||||||
7 | 1.43 | 60 | 18 | 0 | 18 | 65 | 82.4 | 1.65 | |
8 | 1.48 | 60 | 30 | 0 | 0 | 70 | 77.5 | 1.55 | |
9 | 1.51 | 60 | 0 | 13 | 26 | 61 | 87.0 | 1.74 | |
1.51 | 12 | ||||||||
10 | 1.59 | 30 | 0 | 18 | 12 | 69 | 87.8 | 1.76 | |
11 | 1.63 | 60 | 0 | 16 | 11 | 73 | 89.1 | 1.78 | |
12 | 1.75 | 60 | 0 | 10 | 20 | 70 | 90.2 | 1.80 | |
13 | 1.78 | 60 | 9 |
9 | 9 | 73 | 86.6 | 1.73 | |
1.81 | 60 | ||||||||
14 | 1.82 | 60 | 8 | 8 | 8 | 75 | 87.7 | 1.75 | |
15 | 1.87 | 20 | 0 | 16 | 11 | 73 | 89.3 | 1.79 | |
16 | 1.91 | 120 | 0 | 14 | 9 | 77 | 90.8 | 1.82 | |
17 | 2.06 | 60 | 6 | 13 | 2 | 78 | 88.2 | 1.76 | |
18 | 2.07 | 60 | 6 | 6 | 14 | 74 | 88.9 | 1.78 | |
19 | 2.10 | 120 | 0 | 5 | 13 | 82 | 94.1 | 1.88 | |
2.12 | 12 | ||||||||
20 | 2.17 | 20 | 2 | 5 | 11 | 82 | 93.4 | 1.87 | |
2.17 | 60 | ||||||||
21 | 2.19 | 30 | 2 | 3 | 16 | 80 | 93.5 | 1.87 | |
22 | 2.23 | 60 | 2 | 2 | 15 | 81 | 93.9 | 1.88 | |
23 | 2.27 | 60 | 0 | 7 | 14 | 79 | 93.0 | 1.86 | |
24 | 2.33 | 60 | 4 | 4 | 13 | 78 | 91.0 | 1.82 | |
25 | 2.35 | 120 | 0 | 12 | 12 | 75 | 90.8 | 1.82 | |
26 | 2.41 | 120 | 0 | 0 | 23 | 77 | 94.3 | 1.89 | |
2.43 | 12 | ||||||||
27 | 2.47 | 120 | 0 | 7 | 11 | 82 | 93.8 | 1.88 | |
28 | 2.47 | 60 | 0 | 0 | 20 | 80 | 94.9 | 1.90 | |
2.47 | 60 | ||||||||
2.54 | 20 | ||||||||
29 | 2.66 | 60 | 0 | 0 | 20 | 80 | 95.1 | 1.90 | |
2.94 | 12 |
Hydrogen-bonding in expanded water clusters.
Home | Site Index | Icosahedral water clusters | Super-cluster structures | Evidence for icosahedral clusters | LSBU | Top
This page was established in 2003 and last updated by Martin Chaplin on 10 September, 2019