The Born–Mayer equation is an equation that is used to calculate the lattice energy of a crystalline ionic compound. It is a refinement of the Born–Landé equation by using an improved repulsion term.
where: NA = Avogadro constant; M = Madelung constant, relating to the geometry of the crystal; z+ = charge number of cation z− = charge number of anion e = elementary charge, 1.6022 C ε0 = permittivity of free space 4ε0 = 1.112 C2/(J·m) r0 = distance to closest ion ρ = a constant dependent on the compressibility of the crystal; 30 pm works well for all alkali metal halides
See also Born–Landé equation Kapustinskii equation
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