AM_Trimounsite-(Y) Formula: (Y1.534 Er.466) Ti2 Si O9 Name: Trimounsite-(Y) Unit cell: 12.293 11.124 4.861 90.0 95.69 90.0 , V=661.45 Space group: P121/C1 (14)

Kolitsch U , European Journal of Mineralogy , 13 (2001) p.761-768, The crystal structure of trimounsite-(Y), (Y,REE)2Ti2SiO9:, an unusual TiO6-based titanate chain