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Visualisation of a diamond cubic unit cell: 1. Components of a unit cell, 2. One unit cell, 3. A lattice of 3 × 3 × 3 unit cells. Diamond's cubic structure is in the Fd 3 m space group (space group 227), which follows the face-centered cubic Bravais lattice.
In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are arccos (− 1 / 3 ) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane ( CH 4 ) [ 1 ] [ 2 ] as well as its heavier analogues .
Main diamond producing countries. Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic.Diamond as a form of carbon is tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water.
The crystal structure of diamond is a face-centered cubic lattice having eight atoms per unit cell to form a diamond cubic structure. Each carbon atom is covalently bonded to four other carbons in a tetrahedral geometry .
Altogether, the arrangement of atoms in zincblende structure is the same as diamond cubic structure, but with alternating types of atoms at the different lattice sites. The structure can also be described as an FCC lattice of zinc with sulfur atoms occupying half of the tetrahedral voids or vice versa. [6]
Below 13.2 °C, tin exists in the gray form, which has a diamond cubic crystal structure, similar to diamond, silicon or germanium. Gray tin has no metallic properties at all, is a dull gray powdery material, and has few uses, other than a few specialized semiconductor applications. [ 24 ]
The structure has tetrahedral symmetry around each A ion, and the A ions are arranged just like the carbon atoms in diamond. There are another eight tetrahedral sites per unit cell that are empty, each one surrounded by a tetrahedron of B as well as a tetrahedron of X ions.
Figure 1: Classic "Diamond" Structure: Face-Centered Cubic with Tetrahedral Holes Filled with Four Atoms: Figure 2: View A of Nitrogen-vacancy Center: the blue atoms represent Carbon atoms, red atom represents Nitrogen atom substituting for a Carbon atom, and yellow atom represents a lattice vacancy: Figure 3: View B of Nitrogen-vacancy Center