Table 1.
Key information about the cluster ions in the super-LRAP family
| Cluster | VDE (BI), eV | BL (cluster), Å | BL (crystal), Å | R, Å | CS, Å3 per unit cell | LP, Å | t |
| AlH4− | 4.46 (0.73) | 1.64 | 1.67 | 2.66 | 56.27 | 4.73 | 1.03 |
| BH4− | 4.44 (0.56) | 1.24 | 1.22 | 2.03 | 42.74 | 4.00 | 1.04 |
| BF4− | 7.42 (3.69) | 1.44 | 1.42 | 2.43 | 62.48 | 4.72 | 1.10 |
| Cl− | 3.71 (−0.17) | — | — | 1.67 | 31.89 | 3.91* | 1.19 |
| Br− | 3.58 (−0.30) | — | — | 1.82 | 31.33 | 4.02* | 1.12 |
In each case, the channel size (CS) is calculated using the volume of the unit cell minus the volumes of all of the ions inside. The used ionic radii (R) of Li, O, S, B, Al, H, and F are 0.90, 1.26, 1.70, 0.41, 0.68, 0.81, and 1.01 Å, respectively. The volume of a superhalogen ion is defined as the volume of the cube enclosing the superhalogen tetrahedron. The value in the parentheses is the calculated bonding ionicity (BI) measured by the value of the VDE of the superhalogen ions AlH4−/BH4−/BF4− minus the IP of the superalkali ions Li3O+/Li3S+ (3.88/3.72 eV) in (Li3S)(AlH4), (Li3O)(BH4), (Li3S)(BF4), (Li3O)Cl, and (Li3O)Br. (Li3S)(BF4) has the largest bonding ionicity of all; t is the calculated Goldschmidt's tolerance factor. BL is the bond length inside the superhalogens. LP is the calculated lattice parameter of the corresponding crystal.
Experimental values from ref. 25.