AM_Merrillite Formula: Na.23 Ca9 (Mg.8 Fe.2) P6.24 O28 Name: Merrillite Unit cell: 10.2909 10.2909 36.8746 90.0 90.0 120.0 , V=3381.93 Space group: R3C (161)

Hughes J M , Jolliff B L , Gunter M E , American Mineralogist , 91 (2006) p.1547-1552, The atomic arrangement of merrillite from the Fra Mauro Formation, Apollo 14, lunar mission: The first structure of merrillite from the Moon