(above) alpha tin (α-tin, α-Sn or grey tin) with atoms arranged in a diamond like
Tin: graphic of alpha tin (α-tin, α-Sn or grey tin) showing a diamond-like atomic array. This arrangement is stable below about 13 degrees.
Diamond crystal structure is a face centred cube with four additional atoms inside the cube. It is formed when an atom bonds to four neighbours which are positioned at the points of a regular tetrahedron. It is not a close packed arrangement.
Image is 500 pixels across, the originals are 4096 pixels across.