Three-dimensional configuration of points connected by lines used to describe the orderly arrangement of crystal .
Each point represents one or more atoms in the actual crystal. The lattice is divided into a number of identical blocks or cells that are repeated in all directions to form a geometric pattern. Lattices are classified according to their dominant symmetries: isometric, trigonal, hexagonal, tetragonal, orthorhombic, monoclinic, and triclinic. Compounds that exhibit a crystal-lattice structure include sodium chloride (table salt), cesium chloride, and boron nitride. See also solid-state physics .