AM_Apophyllite-(KF)_2
Formula: K Ca4 Si8 O28 F H16
Name: Apophyllite-(KF)
Unit cell: 8.96 8.96 15.8 90.0 90.0 90.0 , V=1268.45
Space group: P4/MNC (128)

Prince E , American Mineralogist , 56 (1971) p.1243-1251, Refinement of the crystal structure of apophyllite III. Determination of the, hydrogen positions by neutron diffraction