Explanation:
you can use Born-Lande equation,
U=-(A×e^2×Z+ ×Z- ×N)\r ×(1-1/n)
here,U=lattice energy
A=madelung constant
n=Born exponent(depends on repulsion between ion)
e=charge of electron
Z+,Z-=charge of cation and anion
r=distance between cation and its neighbour anion in
space lattice
