Values of Born Exponent to be Used in Repulsive Function for Lattice Energy*
| Ion Type | Example | n |
|---|---|---|
| He-He | LiH | 5 |
| Ne-Ne | NaF, MgO | 7 |
| Ar-Ar | KCl, CaS, CuCl | 9 |
| Kr-Kr | RbBr, AgBr | 10 |
| Xe-Xe | CsI | 12 |
*For compounds of mixed ion types, use the average value (e.g., for NaCl, n = 8).
Reference: Huheey, pps. 99-134.