data_global _chemical_name_mineral 'Hardystonite' loop_ _publ_author_name 'Louisnathan S J' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 130 _journal_year 1969 _journal_page_first 427 _journal_page_last 437 _publ_section_title ; Refinement of the crystal structure of hardystonite, Ca2ZnSi2O7 ; _database_code_amcsd 0010703 _chemical_compound_source 'Franklin, New Jersey, USA' _chemical_formula_sum 'Ca2 Zn Si2 O7' _cell_length_a 7.8279 _cell_length_b 7.8279 _cell_length_c 5.0138 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 307.226 _exptl_crystal_density_diffrn 3.391 _symmetry_space_group_name_H-M 'P -4 21 m' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-y,1/2-x,z' 'y,-x,-z' '1/2-x,1/2+y,-z' '-x,-y,z' '1/2+y,1/2+x,z' '-y,x,-z' '1/2+x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Ca 0.33220 0.16780 0.50610 Zn 0.00000 0.00000 0.00000 Si 0.13930 0.36070 0.93940 O1 0.50000 0.00000 0.17710 O2 0.14000 0.36000 0.25510 O3 0.08180 0.18850 0.78470 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 Ca 0.01707 0.01707 0.00968 0.00776 0.00099 0.00099 Zn 0.00776 0.00776 0.00930 0.00000 0.00000 0.00000 Si 0.00621 0.00621 0.00535 -0.00031 0.00060 0.00060 O1 0.03042 0.03042 0.00560 -0.01552 0.00000 0.00000 O2 0.01707 0.01707 0.00879 0.00869 -0.00080 -0.00080 O3 0.04501 0.00528 0.01579 -0.00497 0.00656 -0.00278