data_global _amcsd_formula_title 'Na2CaMg(PO4)2' loop_ _publ_author_name 'Alkemper J' 'Fuess H' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 213 _journal_year 1998 _journal_page_first 282 _journal_page_last 287 _publ_section_title ; The crystal structures of NaMgPO4, Na2CaMg(PO4)2 and Na18Ca13Mg5(PO4)18: new examples for glaserite related structures Note: known as the beta polymorph of Na2CaMg(PO4)2 ; _database_code_amcsd 0011079 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'Na2 Ca Mg P2 O8' _cell_length_a 5.309 _cell_length_b 5.309 _cell_length_c 7.237 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 120 _cell_volume 176.650 _exptl_crystal_density_diffrn 2.823 _symmetry_space_group_name_H-M 'P -3 m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '-y,-x,z' 'y,-x+y,-z' '-x,-x+y,-z' '-x+y,-x,z' '-x+y,y,z' '-x,-y,-z' 'y,x,-z' '-y,x-y,z' 'x,x-y,z' 'x-y,x,-z' 'x-y,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv Na 0.33333 0.66667 0.76600 0.01267 Ca 0.00000 0.00000 0.50000 0.01267 Mg 0.00000 0.00000 0.00000 0.01013 P 0.33333 0.66667 0.24900 0.00507 O1 0.33333 0.66667 0.02900 0.01267 O2 0.17600 -0.17600 0.31000 0.01267