data_global _amcsd_formula_title 'SrGa2Si2O8' loop_ _publ_author_name 'Phillips M W' 'Kroll H' 'Pentinghaus H' 'Ribbe P H' _journal_name_full 'American Mineralogist' _journal_volume 60 _journal_year 1975 _journal_page_first 659 _journal_page_last 666 _publ_section_title ; The structures of synthetic paracelsian analogs, SrGa2Si2O8 and SrGa2Ge2O8 ; _database_code_amcsd 467 _chemical_formula_sum 'Sr Ga2.003 Si1.997 O8' _cell_length_a 9.0009 _cell_length_b 9.484 _cell_length_c 8.3987 _cell_angle_alpha 90.0 _cell_angle_beta 90.682 _cell_angle_gamma 90.0 _cell_volume 716.9 _exptl_crystal_density_diffrn 3.811 _symmetry_space_group_name_H-M 'P 1 21/a 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,z' '1/2-x,1/2+y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Sr 0.8893 0.4131 0.2515 1.0 Ga1 0.2284 0.9257 0.9302 0.996 Si1 0.2284 0.9257 0.9302 0.004 Si2 0.2434 0.9185 0.5596 0.984 Ga2 0.2434 0.9185 0.5596 0.016 Si3 0.0611 0.2017 0.9463 1.0 Ga4 0.053 0.191 0.5732 0.991 Si4 0.053 0.191 0.5732 0.009 O1 0.193 0.098 0.015 1.0 O2 0.1899 0.0692 0.4894 1.0 O3 0.1188 0.3651 0.9397 1.0 O4 0.123 0.3718 0.5594 1.0 O5 0.9268 0.1961 0.0734 1.0 O6 0.893 0.1941 0.4365 1.0 O7 0.0016 0.1449 0.7742 1.0 O8 0.3184 0.9256 0.7367 1.0 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Sr 0.0119 0.00684 0.0075 0.00043 -0.00038 -0.0004 Ga1 0.00698 0.00592 0.00607 0.0 -0.00038 -0.00081 Si1 0.00698 0.00592 0.00607 0.0 -0.00038 -0.00081 Si2 0.00616 0.00547 0.00536 0.00043 0.00038 0.0 Ga2 0.00616 0.00547 0.00536 0.00043 0.00038 0.0 Si3 0.00533 0.00501 0.00464 -0.00086 0.0 -0.00081 Ga4 0.0078 0.00456 0.005 0.0 0.0 0.00081 Si4 0.0078 0.00456 0.005 0.0 0.0 0.00081 O1 0.00985 0.00547 0.00965 0.00173 -0.00191 -0.00121 O2 0.01272 0.00592 0.01072 0.00259 0.00153 0.00202 O3 0.01231 0.00547 0.01108 -0.00389 -0.00038 0.00202 O4 0.01067 0.00684 0.01179 -0.00519 0.00345 0.0004 O5 0.00533 0.01094 0.00929 -0.00173 0.00306 -0.00363 O6 0.00821 0.0082 0.01 -0.00173 -0.00115 0.00282 O7 0.0197 0.01139 0.00643 -0.00649 0.0 -0.0004 O8 0.00985 0.01504 0.00464 -0.00216 0.0023 0.0