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Chemistry

Cubic Cell Calculator

Link atomic radius, lattice parameter and density for simple, body-centred and face-centred cubic crystals.

Your inputs

Change any value to update the result instantly.

Chemistry
pm
g/mol

Lattice parameter a

404.465 pm

Atoms per unit cell Z

4

Theoretical density

2.7084 g/cm³

Unit cell volume

66.1673 nm³ × 10⁻³

Packing efficiency

74.05 %

Geometry used

Atoms touch along the face diagonal

Packing efficiency comes out near 52% for simple cubic, 68% for body-centred and 74% for face-centred, which is the closest packing of equal spheres.

What this calculator does

Links atomic radius, lattice parameter, packing efficiency and theoretical density for cubic unit cells.

What your result means

The edge length of the unit cell and the density that geometry implies.

Formula and working

ρ = Z·M / (N_A·a³); SC a = 2r, BCC a = 4r/√3, FCC a = 2√2·r

  1. 1

    Collect the inputs

    Cubic lattice type = 3; Atomic radius r = 143 pm; Molar mass M = 26.98 g/mol

  2. 2

    Apply the formula

    ρ = Z·M / (N_A·a³); SC a = 2r, BCC a = 4r/√3, FCC a = 2√2·r

  3. 3

    Result

    Lattice parameter a = 404.465 pm

Frequently asked questions

Symbols and assumptions

a
Lattice parameter
Z
Atoms per unit cell
r
Atomic radius
N_A
Avogadro constant
  • Hard-sphere atoms touching along the stated direction.
  • Z is 1, 2 or 4 for simple, body-centred and face-centred cubic.

Sources and review

Reviewed 2026-09-22 · Next review 2027-09-22

  • Real crystals have defects and thermal expansion, so measured density is slightly lower.

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.

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