Romarchite Pannetier J, Denes G Acta Crystallographica B36 (1980) 2763-2765 Tin(II) oxide: structure refinement and thermal expansion _database_code_amcsd 0009724 3.8029 3.8029 4.8382 90 90 90 P4/nmm atom x y z Biso Sn .5 0 .2383 .57 O 0 0 0 .99