AM_Trolleite
Formula: Al4 P3 O15 H3
Name: Trolleite
Unit cell: 18.894 7.161 7.162 90.0 99.99 90.0 , V=954.33
Space group: I12/C1 (15)

Moore P B , Araki T , American Mineralogist , 59 (1974) p.974-984, Trolleite, Al4(OH)3[PO4]3: A very dense structure with octahedral, face-sharing dimers