A type of ionic crystal structure in which the anions are at the eight corners of a cubic unit cell with one cation at the centre of the cell. It can equivalently be described as cations at the corners of the cell with an anion at the centre. Each type of ion has a coordination number of 8. Examples of compounds with this structure are CsCl, CsBr, CsI, CsCN, CuZn, and NH4Cl.