data_global _chemical_name_mineral 'Bassanite' loop_ _publ_author_name 'Ballirano P' 'Maras A' 'Meloni S' 'Caminiti R' _journal_name_full 'European Journal of Mineralogy' _journal_volume 13 _journal_year 2001 _journal_page_first 985 _journal_page_last 993 _publ_section_title ; The monoclinic I2 structure of bassanite, calcium sulphate hemihydrate ; _database_code_amcsd 0006909 _chemical_formula_sum 'Ca2 S2 O9 H2' _cell_length_a 12.0350 _cell_length_b 6.9294 _cell_length_c 12.6705 _cell_angle_alpha 90 _cell_angle_beta 90.266 _cell_angle_gamma 90 _cell_volume 1056.649 _exptl_crystal_density_diffrn 2.737 _symmetry_space_group_name_H-M 'I 1 2 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '-x,y,-z' '1/2-x,1/2+y,1/2-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Ca1 0.00000 0.50000 0.00000 0.01153 Ca2 0.50000 0.01100 0.00000 0.01153 Ca3 0.23800 0.19900 0.16770 0.01153 Ca4 0.22170 0.16500 0.66480 0.01153 S1 -0.00160 0.49900 0.24930 0.00950 S2 0.22470 0.16400 0.91830 0.00950 S3 0.22820 0.18500 0.41460 0.00950 O1 0.12700 0.21100 0.98400 0.01140 O2 0.12500 0.23000 0.47300 0.01140 O3 0.07400 0.61600 0.31500 0.01140 O4 0.07500 0.62000 0.81600 0.01140 O5 0.19600 0.04400 0.33200 0.01140 O6 0.20500 -0.01500 0.85800 0.01140 O7 0.05700 0.36600 0.17800 0.01140 O8 0.05800 0.37600 0.67300 0.01140 O9 0.27200 0.35900 0.36100 0.01140 O10 0.23800 0.31700 0.83800 0.01140 O11 0.31900 0.16100 0.99100 0.01140 O12 0.30800 0.10300 0.49100 0.01140 Wat1 0.00000 0.84300 0.00000 0.08106 Wat2 0.95300 0.00400 0.35300 0.08106