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: Room pressure, 23 C, (800 C quenched) ; _database_code_amcsd 0001846 _chemical_formula_sum '(Ni Mg) Si O4' _cell_length_a 4.7362 _cell_length_b 10.1682 _cell_length_c 5.9401 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 286.067 _exptl_crystal_density_diffrn 4.065 _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 0.74200 0.01500 Mg1 0.00000 0.00000 0.00000 0.25800 0.01500 Ni2 0.98980 0.27520 0.25000 0.25800 0.01500 Mg2 0.98980 0.27520 0.25000 0.74200 0.01500 Si 0.42560 0.09320 0.25000 1.00000 0.01700 O1 0.77190 0.09160 0.25000 1.00000 0.00900 O2 0.22080 0.44470 0.25000 1.00000 0.00900 O3 0.27680 0.16400 0.03190 1.00000 0.00900