data_global _chemical_name_mineral 'Walstromite' loop_ _publ_author_name 'Dent Glasser L S' 'Glasser F P' _journal_name_full 'American Mineralogist' _journal_volume 53 _journal_year 1968 _journal_page_first 9 _journal_page_last 13 _publ_section_title ; The crystal structure of walstromite ; _database_code_amcsd 165 _chemical_formula_sum 'Ca2 Ba Si3 O9' _cell_length_a 6.733 _cell_length_b 9.616 _cell_length_c 6.723 _cell_angle_alpha 69.62 _cell_angle_beta 102.33 _cell_angle_gamma 96.9 _cell_volume 398.121 _exptl_crystal_density_diffrn 3.718 _symmetry_space_group_name_H-M 'P -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Ca1 0.272 0.507 0.763 Ca2 0.435 0.831 0.935 Ba 0.049 0.848 0.323 Si1 0.096 0.222 0.145 Si2 0.235 0.484 0.284 Si3 0.442 0.196 0.511 O1 0.236 0.251 -0.027 O2 -0.098 0.114 0.102 O3 0.042 0.366 0.212 O4 0.366 0.556 0.089 O5 0.125 0.58 0.389 O6 0.352 0.365 0.494 O7 0.613 0.238 0.368 O8 0.517 0.084 0.765 O9 0.238 0.13 0.389