rocksaltStrukturen

Rocksaltstruktur (or "rocksalt structure") is a common crystalline arrangement observed in various ionic compounds, most notably in sodium chloride (NaCl). This structure is characterized by a face-centered cubic (FCC) lattice where each ion is surrounded by six ions of the opposite charge in an octahedral coordination.

In the rocksalt structure, the cations and anions are arranged in a regular, repeating pattern, forming an extensive three-dimensional network. The basis consists of two interpenetrating FCC lattices, one of positive ions and one of negative ions, offset by a quarter of the cell length along each axis. This configuration ensures neutrality and maximizes ionic stability.

The coordination number for both types of ions in this structure is six, meaning each ion is directly bonded to six ions of the opposite charge. The ions are typically spherical and packed closely together, resulting in high melting points and significant lattice energies, which contribute to the compound's stability.

This structure is prevalent among binary ionic compounds with small, highly charged ions. Crystals with rocksalt structures often display high hardness and good cleavage along specific planes due to their regular lattice arrangement. Aside from NaCl, compounds like potassium chloride (KCl) and calcium oxide (CaO) also adopt the rocksalt structure.

The rocksalt structure provides a fundamental model in solid-state chemistry and materials science for understanding ionic solids, their properties, and their stability. Its simplicity and stability make it a key reference point in the study of crystalline ionic materials.