Professor YANG Zhuming and his team study the crystal structure of nanlingite. They find that nanlingite is the first mineral with a [Fe(AsO3)6] configuration.
The structure was solved and refined on single-crystal X-ray data. The complex framework is formed by edge- and corner-sharing of distorted NaF8 and CaF4O4 cubes, MgF2O4 octahedra, and AsO3 trigonal pyramids. This [Fe(AsO3)6] cluster is a novel configuration in the crystal chemistry of minerals. The chemical formula of nanlingite is Na(Ca, Li, Na)6(Mg, Fe)12(AsO3)2[Fe(AsO3)6] F14 with Z=3 according to the crystal structure refinement.
Yang et al. Crystal structure of nanlingite – the first mineral with a [Fe(AsO3)6] configuration. European Journal of Mineralogy. 2011，23: 63-71 (Download Here)
Fig. Perspective view of the nanlingite structure. The red octahedral are occupied by Fe. The yellow distorted cubes illustrate NaF8. The light and dark blue octahedra are occupied by Mg. The Ca atoms are shown as small green spheres. As-O bonds are given in yellow. (Image by YANG)
