Silicon has the diamond cubic crystal structure with a lattice parameter of 0.543 nm. The nearest neighbor distance is 0.235 nm. The diamond cubic crystal structure has an fcc lattice with a basis of ...

(Top diagram) Diamond is metastable at room temperature and has a diamond cubic crystal structure. (Lower diagram) The diamond cubic structure is a face-centered-cubic lattice with a basis of two ...

because while diamond forms with a tetrahedral arrangement in its carbon lattice (known as diamond cubic), lonsdaleite forms a hexagonal one that increases thermal stability and hardness.

The first diamond made by the group was millimeter-sized and was tested at 155 GPa, with thermal stability up to 1,100°C. Natural diamonds typically range from 70 to 100 GPa and can only ...