What is a primitive unit cell?

Unit cell

• The unit cell, or building block of a crystal, is the smallest repeating unit in the crystal lattice.
• It can be of different types: primitive cubic, body-centered cubic (BCC), or face-centered cubic unit cell.

Primitive Cubic Unit Cell

• Only the corners of the primitive cubic unit cell have atoms, and each atom at the corner is shared by eight adjacent unit cells.
• The simple cubic (SC) unit cell can be described as a cube with an atom on each corner.
• Thus, each small sphere represents the center of a particle that occupies that particular position, not its size, and each unit cell has the only $1/8^{\mathrm{th}}$part of an atom.
• The number of atoms will be 1.

Example of simple cubic unit cell is Polonium metal.