data_global _chemical_name_mineral 'Heulandite' loop_ _publ_author_name 'Gunter M E' 'Armbruster T' 'Kohler T' 'Knowles C R' _journal_name_full 'American Mineralogist' _journal_volume 79 _journal_year 1994 _journal_page_first 675 _journal_page_last 682 _publ_section_title ; Crystal structure and optical properties of Na- and Pb-exchanged heulandite-group zeolites Sample: Pb-exchanged Atomic parameters from ICSD ; _database_code_amcsd 0001670 _chemical_formula_sum '(Si13.554 Al4.446) O44.08 Pb2' _cell_length_a 17.767 _cell_length_b 17.917 _cell_length_c 7.432 _cell_angle_alpha 90 _cell_angle_beta 116.33 _cell_angle_gamma 90 _cell_volume 2120.393 _exptl_crystal_density_diffrn 2.538 _symmetry_space_group_name_H-M 'C 1 m 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,z' '1/2+x,1/2-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 Si1 0.17960 0.16950 0.09100 0.75300 0.01317 Al1 0.17960 0.16950 0.09100 0.24700 0.01317 Si2 0.82220 0.83150 -0.09400 0.75300 0.01279 Al2 0.82220 0.83150 -0.09400 0.24700 0.01279 Si3 0.28740 0.08940 0.49300 0.75300 0.01241 Al3 0.28740 0.08940 0.49300 0.24700 0.01241 Si4 0.71610 -0.09030 0.50300 0.75300 0.01748 Al4 0.71610 -0.09030 0.50300 0.24700 0.01748 Si5 0.29610 0.30810 0.28800 0.75300 0.01305 Al5 0.29610 0.30810 0.28800 0.24700 0.01305 Si6 0.71050 0.69190 0.71800 0.75300 0.01317 Al6 0.71050 0.69190 0.71800 0.24700 0.01317 Si7 0.06700 0.29910 0.41700 0.75300 0.01191 Al7 0.06700 0.29910 0.41700 0.24700 0.01191 Si8 -0.06340 0.69800 0.58900 0.75300 0.01393 Al8 -0.06340 0.69800 0.58900 0.24700 0.01393 Si9 0.00000 0.21600 0.00000 0.75300 0.01646 Al9 0.00000 0.21600 0.00000 0.24700 0.01646 O1 0.29900 0.00000 0.55500 1.00000 0.03040 O2 0.19900 0.50000 0.45800 1.00000 0.02786 O3 0.23510 0.12480 0.61300 1.00000 0.03166 O4 0.77620 0.87700 0.40300 1.00000 0.03293 O5 0.18800 0.15080 0.88500 1.00000 0.04053 O6 0.81930 0.84820 0.11700 1.00000 0.02280 O7 0.23100 0.10170 0.24500 1.00000 0.04053 O8 0.76110 0.89480 0.75200 1.00000 0.01520 O9 0.00000 0.32800 0.50000 1.00000 0.02913 O10 0.08200 0.16230 0.04700 1.00000 0.03673 O11 -0.08240 0.84140 -0.06700 1.00000 0.01520 O12 0.38070 0.26540 0.45300 1.00000 0.03166 O13 0.63100 0.73680 0.55800 1.00000 0.03420 O14 0.00990 0.26430 0.19400 1.00000 0.03420 O15 -0.01230 0.72570 0.81700 1.00000 0.03166 O16 0.21180 0.25260 0.17800 1.00000 0.02913 O17 0.78910 0.74780 0.82900 1.00000 0.02786 O18 0.11870 0.37260 0.40100 1.00000 0.01900 O19 0.88200 0.62500 0.58000 1.00000 0.04179 Pb1 0.15050 0.00000 0.67900 0.32000 0.06839 Pb2 0.85200 0.00000 0.32700 0.40000 0.05573 Pb3 0.03810 0.50000 0.19790 0.60000 0.03762 Pb4 0.21700 0.00000 0.87700 0.14000 0.08106 Pb5 0.79400 0.00000 0.14000 0.12000 0.06206 Pb6 -0.01100 0.07680 0.66700 0.14000 0.16085 Pb7 0.00900 0.90000 0.48400 0.07000 0.16085 O20 0.42180 0.08730 0.03400 1.00000 0.03673 O21 0.01700 0.07400 0.32200 0.76000 0.02533 O22 0.49900 0.00000 0.50200 1.00000 0.10639 O23 -0.07600 0.00000 0.12100 0.88000 0.09638 O24 0.07700 0.00000 0.26800 1.14000 0.11766 O25 0.27400 0.00000 -0.00400 0.60000 0.02786 O26 0.72400 0.00000 -0.01800 0.86000 0.11019 O27 0.29000 0.00000 0.25000 0.22000 0.08004