Madelung Constants

Compound
Crystal Lattice
M
NaCl NaCl 1.74756
CsCl CsCl 1.76267
CaF2 Cubic 2.51939
CdCl2 Hexagonal 2.244
MgF2 Tetragonal 2.381
ZnS (wurtzite) Hexagonal 1.64132
TiO2 (rutile) Tetragonal 2.408
bSiO2 Hexagonal 2.2197
Al2O3 Rhombohedral 4.1719