The space group is I4/mmm, z= 2. Powder neutron diffraction studies on this system has been performed to determine the possible ordering of the Co and Mn atoms on 3 nonequivalent crystallo-graphic sites 8i, 8j and 8f.

• 用粉末中子衍射测定了Co,Mn原子在8i,8j和8f晶位上的有序度。