Chemistry

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Lattice Energy Calculator.

Calculate Born–Landé lattice energy from entered charges, separation, and crystal-model constants.

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Set your values

Results update as you type.

How to Use

U = −Nₐ A |z₊z₋| e² /(4π ε₀ r₀) × (1 − 1/n).

Every material coefficient and convention is an input. No element, fluid, lab-method, or safety database is queried; results update after a short debounce.

Use Cases

Compare stability of ionic compounds

Use the calculator to compare lattice energies of different salts, helping to understand their relative stability and physical properties.

Example: Compare NaCl and MgO to see why MgO has a much higher melting point.

Educational practice in chemistry

Students can verify textbook examples or homework problems by entering known values for ionic crystals and checking the calculated lattice energy.

Example: Calculate the lattice energy of NaCl using its standard parameters.

Frequently Asked Questions

What is the Born–Landé equation?
The Born–Landé equation estimates the lattice energy of an ionic crystal. It uses the charges of the ions, the distance between them, and constants like the Madelung constant and Born exponent to compute the energy released when the crystal forms from gaseous ions.
What inputs do I need for this calculator?
You need the charges of the cation and anion, the interionic separation (distance between ions), and the crystal model constants, which include the Madelung constant and the Born exponent. These are typically known for common crystal structures like NaCl or CsCl.
Why is lattice energy important?
Lattice energy indicates the strength of ionic bonding. Higher lattice energy means a more stable crystal and higher melting point. It also helps predict solubility and reactivity of ionic compounds.

Tips & Common Mistakes

Tips

  • Ensure the charges are entered as integers (e.g., +1, -2) and not as decimals.
  • Use consistent units for interionic separation, typically picometers (pm) or angstroms (Å).
  • Double-check the Madelung constant for your crystal structure (e.g., NaCl = 1.74756, CsCl = 1.76267).
  • The Born exponent varies with ion type; common values range from 5 to 12.

Common Mistakes to Avoid

  • Forgetting to convert interionic separation to meters if the formula requires SI units.
  • Using the wrong Madelung constant for the crystal structure, leading to incorrect results.
  • Entering charges as absolute values instead of signed values, which can affect the sign of the energy.

Last updated: August 13, 2026