data_global _chemical_name_mineral 'Wadsleyite' loop_ _publ_author_name 'Jacobsen S D' 'Demouchy S' 'Frost D J' 'Ballaran T B' 'Kung J' _journal_name_full 'American Mineralogist' _journal_volume 90 _journal_year 2005 _journal_page_first 61 _journal_page_last 70 _publ_section_title ; A systematic study of OH in hydrous wadsleyite from polarized FTIR spectroscopy and single-crystal X-ray diffraction: Oxygen sites for hydrogen storage in Earth's interior Sample: ~9600 wt ppm H2O ; _database_code_amcsd 0003665 _chemical_formula_sum 'Mg2 Si O4' _cell_length_a 5.6890 _cell_length_b 11.4830 _cell_length_c 8.2527 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 539.122 _exptl_crystal_density_diffrn 3.467 _symmetry_space_group_name_H-M 'I m m a' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' 'x,1/2-y,z' '1/2+x,-y,1/2+z' '-x,1/2+y,-z' '1/2-x,+y,1/2-z' '-x,y,z' '1/2-x,1/2+y,1/2+z' 'x,-y,-z' '1/2+x,1/2-y,1/2-z' 'x,1/2+y,-z' '1/2+x,+y,1/2-z' '-x,1/2-y,z' '1/2-x,-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 Mg1 0.00000 0.00000 0.00000 0.00804 Mg2 0.00000 0.25000 0.97013 0.00584 Mg3 0.25000 0.12516 0.25000 0.00660 Si 0.00000 0.12033 0.61619 0.00460 O1 0.00000 0.25000 0.21995 0.00702 O2 0.00000 0.25000 0.71649 0.00622 O3 0.00000 0.98863 0.25578 0.00663 O4 0.26092 0.12317 0.99359 0.00615 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 Mg1 0.00930 0.00490 0.00990 0.00000 0.00000 0.00090 Mg2 0.00730 0.00480 0.00540 0.00000 0.00000 0.00000 Mg3 0.00540 0.00840 0.00600 0.00000 -0.00077 0.00000 Si 0.00479 0.00470 0.00432 0.00000 0.00000 -0.00017 O1 0.00510 0.00840 0.00760 0.00000 0.00000 0.00000 O2 0.00850 0.00610 0.00400 0.00000 0.00000 0.00000 O3 0.00680 0.00740 0.00580 0.00000 0.00000 0.00070 O4 0.00560 0.00670 0.00620 0.00030 0.00071 0.00030