data_global _chemical_name_mineral 'Tephroite' loop_ _publ_author_name 'Fujino K' 'Sasaki S' 'Takeuchi Y' 'Sadanaga R' _journal_name_full 'Acta Crystallographica, Section B' _journal_volume 37 _journal_year 1981 _journal_page_first 513 _journal_page_last 518 _publ_section_title ; X-ray determination of electron distributions in forsterite, fayalite and tephroite ; _database_code_amcsd 0019695 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Mn2 Si O4' _cell_length_a 4.9023 _cell_length_b 10.5964 _cell_length_c 6.2567 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 325.015 _exptl_crystal_density_diffrn 4.127 _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_U_iso_or_equiv Mn1 0.00000 0.00000 0.00000 0.00785 Mn2 0.98792 0.28041 0.25000 0.00673 Si 0.42755 0.09643 0.25000 0.00484 O1 0.75776 0.09363 0.25000 0.00680 O2 0.21088 0.45369 0.25000 0.00686 O3 0.28706 0.16384 0.04140 0.00733