#50
Pban
Example – Retzian, Mn2(Nd,Ce,La,Y)(OH)4(AsO4)
Named for Anders Jahan Retzius (1742-1821), Swedish naturalist.
Crystal chemistry of the basic manganese arsenate minerals 1. The crystal
structures of flinkite, Mn2Mn(OH)4(AsO4) and retzian, Mn2Y(OH)4(AsO4)
Moore P.B.
American Mineralogist 52 (1967) 1603-1613
http://webmineral.com/data/Retzian-(Nd).shtml
CIF
https://www.dropbox.com/s/kgr83k1zorxvrrf/amcsd%200000161.cif
MnO6 octahedra (pink)
AsO4 tetrahedra (green)
Y/RE (blue)
The Fascination of Crystals and Symmetry 