data_global _chemical_name_mineral 'Liebenbergite' loop_ _publ_author_name 'Chen J' 'Li R' 'Parise J B' 'Weidner D J' _journal_name_full 'American Mineralogist' _journal_volume 81 _journal_year 1996 _journal_page_first 1519 _journal_page_last 1522 _publ_section_title ; Pressure-induced ordering in (Ni,Mg)2SiO4 olivine Sample: 4 GPa and 800 C, 109 min ; _database_code_amcsd 0001849 _chemical_formula_sum '(Ni Mg) Si O4' _cell_length_a 4.7322 _cell_length_b 10.1453 _cell_length_c 5.9309 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 284.740 _exptl_crystal_density_diffrn 4.084 _symmetry_space_group_name_H-M 'P b n m' loop_ _space_group_symop_operation_xyz 'x,y,z' 'x,y,1/2-z' '-x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '1/2-x,1/2+y,1/2-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 _atom_site_U_iso_or_equiv Ni1 0.00000 0.00000 0.00000 0.76200 0.01600 Mg1 0.00000 0.00000 0.00000 0.23800 0.01600 Ni2 0.98920 0.27620 0.25000 0.23800 0.01600 Mg2 0.98920 0.27620 0.25000 0.76200 0.01600 Si 0.42600 0.09390 0.25000 1.00000 0.01700 O1 0.76870 0.08900 0.25000 1.00000 0.01000 O2 0.22590 0.44500 0.25000 1.00000 0.01000 O3 0.28040 0.16260 0.03260 1.00000 0.01000