The crystal structure of leisingite, (Cu (super 2+) ,Mg,Zn) (sub 2) (Mg,Fe)Te (super 6+) O (sub 6) .6H (sub 2) O

The crystal structure of leisingite (a 5.316, c 9.719 Aa, V 237.8 Aa (super 3) , space group P<$E 3 back 40 up 40 ->lm, Z = 1) from the type specimen has been refined to R 4.2. There are three distinct cation positions, all cations being in octahedral coordination with oxygen. One position is fully occupied by Te (super 6+) , the Cu site shows Mg substitution and the Mg site contains a substantial amount of Fe. Sheets of stoichiometry (Cu (super 2+) ,Mg,Zn) (sub 2) Te (super 6+) O (sub 6) form along the (001) faces of the unit cell; the Mg site is halfway between these sheets, with the stoichiometry of (Mg,Fe)<P6M><P255>6H (sub 2) O. The sheets are connected to these isolated octahedra by hydrogen bonding, which accounts for the perfect 001 cleavage.