SO3 Westrik R, MacGillavry C H Acta Crystallographica 7 (1954) 764-767 The crystal structure of the asbestos-like form of sulphur trioxide _database_code_amcsd 0009159 6.20 4.06 9.31 90 109.83 90 P2_1/c atom x y z S .171 .025 .294 O1 .001 .275 .169 O2 .270 .20 .431 O3 .281 -.15 .207