data_global _chemical_name_mineral 'Sursassite' loop_ _publ_author_name 'Gottschalk M' 'Fockenberg T' 'Grevel K-D' 'Wunder B' 'Wirth R' 'Schreyer W' 'Maresch W V' _journal_name_full 'European Journal of Mineralogy' _journal_volume 12 _journal_year 2000 _journal_page_first 935 _journal_page_last 945 _publ_section_title ; Crystal structure of the high-pressure phase Mg4(MgAl)Al4[Si6O21/(OH)7]: an analogue of sursassite Sample: A53 ; _database_code_amcsd 0006842 _chemical_formula_sum 'Mg2.42 Al2.58 Si3 O14 H3.42' _cell_length_a 8.5424 _cell_length_b 5.7117 _cell_length_c 9.6484 _cell_angle_alpha 90 _cell_angle_beta 108.298 _cell_angle_gamma 90 _cell_volume 446.958 _exptl_crystal_density_diffrn 3.270 _symmetry_space_group_name_H-M 'P 1 21/m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,1/2-y,z' '-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 _atom_site_U_iso_or_equiv MgM1 0.18040 0.25000 0.31540 1.00000 0.00500 MgM2 0.27650 0.25000 0.67180 1.00000 0.00600 AlM3 0.50000 0.00000 0.50000 0.58000 0.01800 MgM3 0.50000 0.00000 0.50000 0.42000 0.01800 AlM4 0.50000 0.00000 0.00000 1.00000 0.00500 AlM5 0.00000 0.00000 0.00000 1.00000 0.00400 SiT1 0.30600 0.75000 0.19480 1.00000 0.01120 SiT2 0.20680 0.75000 0.80670 1.00000 0.01120 SiT3 0.14920 0.75000 0.49300 1.00000 0.01120 O1 0.25100 0.50800 0.49800 1.00000 0.00540 O2 0.18980 0.52200 0.17070 1.00000 0.00540 O3 0.31600 0.51400 0.82430 1.00000 0.00540 O4 0.40700 0.75000 0.07650 1.00000 0.00540 O5 0.45700 0.75000 0.35860 1.00000 0.00540 O6 0.08900 0.25000 0.92790 1.00000 0.00540 O7 0.44200 0.25000 0.36320 1.00000 0.00540 O8 0.08000 0.75000 0.89970 1.00000 0.00540 O9 0.07600 0.75000 0.63570 1.00000 0.00540 O10 -0.02600 0.75000 0.35490 1.00000 0.00540 O11 0.40200 0.25000 0.06630 1.00000 0.00540 H1 0.14500 0.25000 0.03400 1.00000 0.01000 H2 0.36100 0.25000 0.26300 0.42000 0.01000 H3 -0.10700 0.75000 0.25700 1.00000 0.01000 H4 0.48000 0.25000 0.16600 1.00000 0.01000