Engineering Physics

2.12 Zinc sulphide [ZnS] structure

This is an ionic compound. This structure consists of two different types of atoms. The Bravais lattice of ZnS is a face-centred cube. The crystal structure of ZnS is considered as the interpenetration of two FCC sub-lattices along the body diagonal such that the origin of one sub-lattice is at a distance of 1/4th the body diagonal from the origin along the body diagonal. One sub-lattice contains Zn atoms and other sub-lattice contains S atoms. The ZnS crystal structure is similar to diamond crystal structure. The unit cell contains four ZnS molecules. Each atom is surrounded by four other kind of atoms at the corners of a regular tetrahedron. The co-ordinates of S atom is and that of Zn atoms co-ordinates ...