Consider a real unit cell with axes a and b separated by the angle γ. The interplanar spacing d₁₀₀ is perpendicular to (100) planes and d₀₁₀ perpendicular to (010) planes.

In reciprocal space, the lattice vector a* is parallel to d₁₀₀,
b* to d₀₁₀ and angle γ* = 180 − γ

The reciprocal lattice vectors, a* and b* have lengths which are the reciprocals of the interplanar spacings.

Note: the real and reciprocal space lattices are not plotted on the same scale.

The reciprocal unit cell can repeat just like a real unit cell