Chemistry
Lattice Energy Calculator
Estimate the lattice energy of an ionic crystal with the Born-Landé model.
Your inputs
Change any value to update the result instantly.
Lattice energy U
-756 kJ/mol
Magnitude
756 kJ/mol
Charge product z⁺z⁻
1
Repulsion correction (1 − 1/n)
0.875
Sign convention
Negative means energy is released when the free ions come together to form the crystal
Reading
Typical of a simple ionic solid
The Madelung constant is fixed by the crystal geometry: 1.74756 for rock salt, 1.76267 for caesium chloride, 1.63806 for zinc blende. The Born exponent comes from compressibility data.
What this calculator does
Estimates ionic lattice energy with the Born-Landé model from the Madelung constant, ionic charges and separation.
What your result means
A large negative value means a strongly bound crystal with a high melting point.
Formula and working
U = −(N_A · M · z⁺z⁻ · e²) / (4πε₀r₀) × (1 − 1/n)
- 1
Collect the inputs
Madelung constant M = 1.7476; Cation charge z⁺ = 1; Anion charge z⁻ = 1; Nearest-neighbour distance r₀ = 281 pm; Born exponent n = 8
- 2
Apply the formula
U = −(N_A · M · z⁺z⁻ · e²) / (4πε₀r₀) × (1 − 1/n)
- 3
Result
Lattice energy U = -756 kJ/mol
Frequently asked questions
Symbols and assumptions
- U
- Lattice energy
- M
- Madelung constant
- r0
- Nearest-neighbour distance
- n
- Born exponent
- • Purely ionic bonding with spherical ions.
- • The Madelung constant matches the crystal geometry entered.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Covalent character and polarisation are ignored, so real values differ from Born-Haber cycle results.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
Tell us if a formula, unit, explanation, or result needs attention. Your message will include this calculator’s name and page.
Related calculators
Ionic Strength Calculator
Add up the ionic strength of a solution from the concentration and charge of each ion.
Cubic Cell Calculator
Link atomic radius, lattice parameter and density for simple, body-centred and face-centred cubic crystals.
Miller Indices Calculator
Convert plane intercepts into Miller indices and find the spacing between planes in a cubic crystal.
Activity Coefficient Calculator
Estimate the activity coefficient of an ion in a dilute solution using the Debye-Hückel limiting law.
Actual Yield Calculator
Find the mass of product you should expect to collect from a known percent yield.
Air-Fuel Ratio (AFR) Calculator
Calculate the stoichiometric air-to-fuel mass ratio for any CₓHᵧO_z fuel from its carbon, hydrogen and oxygen counts.