AM_Thoreaulite
Formula: Sn Ta2 O7
Name: Thoreaulite
Unit cell: 17.14 4.865 5.548 90.0 91.0 90.0 , V=462.56
Space group: C12/C1 (15)

Mumme W G , American Mineralogist , 55 (1970) p.367-377, The crystal structure of SnTa2O7, thoreaulite, an example of tin in five-fold, coordination