H11, spinel

Structural typeH11
Common namespinel
Definitiondistorted fcc lattice of anions with A cations occupying 1/8 tetrahedral voids
 and B cations occupying ½ octahedral voids
PrototypeMgAl2O4
Pearson symbolcF56
Space group227 Fd-3m Oh7
Chemical formulaA2BX4
Bondingionic
Atomic positions A  (8a)  1/8  1/8  1/8   (marked by C)
 B (16d)  1/2  1/2  1/2   (marked by N)
 X (32e)  xi   xi   xi    (marked by S)
Coordination
SublatticesX – distorted fcc
PDB filesH1_1 (in ideal coordination)
Parametersξ≈.25
Special valuesideal fcc lattice of anions for ξ=1/4
SubstancesIII+II+VI (MgAl2O4), Fe2MnO4, Mn2ZnTe4, ZnV2O4 (low-T);
A3X4 (Fe3O4)