data_global _chemical_name_mineral 'Gonnardite' loop_ _publ_author_name 'Lee Y' 'Hriljac J A' 'Vogt T' _journal_name_full 'American Mineralogist' _journal_volume 90 _journal_year 2005 _journal_page_first 247 _journal_page_last 251 _publ_section_title ; Variable-temperature structural studies of tetranatrolite from Mt. Saint-Hilaire: Synchrotron X-ray powder diffraction and Rietveld analysis Sample: T = 300 C, phase I ; _database_code_amcsd 0003725 _chemical_formula_sum '(Si2.685 Al2.315) O12 Na1.462 Ca.474 H4' _cell_length_a 12.9202 _cell_length_b 12.9202 _cell_length_c 6.6950 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1117.607 _exptl_crystal_density_diffrn 2.297 _symmetry_space_group_name_H-M 'I -4 2 d' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,1/2+z' '1/2-y,-x,3/4+z' '-y,1/2-x,1/4+z' 'y,-x,-z' '1/2+y,1/2-x,1/2-z' '-x,1/2+y,1/4-z' '1/2-x,+y,3/4-z' '-x,-y,z' '1/2-x,1/2-y,1/2+z' '1/2+y,x,3/4+z' '+y,1/2+x,1/4+z' '-y,x,-z' '1/2-y,1/2+x,1/2-z' 'x,1/2-y,1/4-z' '1/2+x,-y,3/4-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 SiT1 0.00000 0.00000 0.00000 0.53700 0.04800 AlT1 0.00000 0.00000 0.00000 0.46300 0.04800 SiT2 0.05100 0.13600 0.62500 0.53700 0.04800 AlT2 0.05100 0.13600 0.62500 0.46300 0.04800 O1 0.39200 0.25000 0.12500 1.00000 0.02600 O2 0.12600 0.06900 0.47600 1.00000 0.02600 O3 0.04500 0.09700 0.86200 1.00000 0.02600 Na 0.68700 0.25000 0.12500 0.73100 0.04600 Ca 0.68700 0.25000 0.12500 0.23700 0.04600 Wat4 0.13400 0.25000 0.12500 1.00000 0.04600