data_global _chemical_name_mineral 'Gunterblassite' loop_ _publ_author_name 'Rastvetaeva R K' 'Aksenov S M' 'Chukanov N V' _journal_name_full 'Doklady Chemistry' _journal_volume 442 _journal_year 2012 _journal_page_first 57 _journal_page_last 62 _publ_section_title ; Crystal structure of gunterblassite, a new mineral with a triple tetrahedral layer Note: tetrahedral sites, Si8.83 Al3.06, but occupancies were not reported ; _database_code_amcsd 0018694 _chemical_compound_source 'Rother Kopf mountain, Eifel volcanic field, Germany' _chemical_formula_sum 'K1.2 Ca.7 Ba.3 Fe.5 Mg.15 Na.15 Si13 O36 H18' _cell_length_a 6.538 _cell_length_b 6.975 _cell_length_c 37.26 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 1699.151 _exptl_crystal_density_diffrn 2.170 _symmetry_space_group_name_H-M 'P n m 21' loop_ _space_group_symop_operation_xyz 'x,y,z' '-x,1/2+y,1/2+z' 'x,-y,z' '-x,1/2-y,1/2+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 K1 0.07200 0.00000 0.22790 0.35000 0.02913 Ca1 0.07200 0.00000 0.22790 0.25000 0.02913 K2 0.10100 0.00000 0.04690 0.50000 0.01520 Ba2 0.10100 0.00000 0.04690 0.30000 0.01520 K3 0.22900 0.50000 0.42250 0.35000 0.04053 Ca3 0.22900 0.50000 0.42250 0.25000 0.04053 Fe 0.24600 0.50000 0.86850 0.50000 0.03166 Ca 0.24600 0.50000 0.86850 0.20000 0.03166 Mg 0.24600 0.50000 0.86850 0.15000 0.03166 Na 0.24600 0.50000 0.86850 0.15000 0.03166 Si1 0.38400 0.00000 0.82110 1.00000 0.02026 Si2 0.19900 0.21800 0.31630 1.00000 0.02153 Si3 0.01300 0.00000 0.77080 1.00000 0.03293 Si4 0.42900 0.00000 0.63880 1.00000 0.01393 Si5 0.05500 0.00000 0.69040 1.00000 0.01267 Si6 0.20700 0.22100 0.14000 1.00000 0.02786 Si7 0.02800 0.00000 0.57740 1.00000 0.01520 Si8 0.04700 0.00000 0.49150 1.00000 0.01520 Si9 0.21000 0.23300 0.94620 1.00000 0.02533 Si10 0.43700 0.00000 0.44630 1.00000 0.01520 O1 0.45300 0.31600 0.14200 1.00000 0.02153 O2 0.24000 0.00000 0.60600 1.00000 0.06839 O3 0.09000 0.32300 0.17770 1.00000 0.02406 O4 0.05500 0.00000 0.72940 1.00000 0.03926 O5 0.05200 0.31000 0.10500 1.00000 0.02786 O6 0.22500 0.00000 0.14400 1.00000 0.02153 O7 0.43800 0.31100 0.32280 1.00000 0.03420 O8 0.26000 0.00000 0.78300 1.00000 0.02026 O9 0.12800 0.31600 0.98380 1.00000 0.03926 O10 0.09800 0.28900 0.28230 1.00000 0.01646 O11 0.07100 0.00000 0.53370 1.00000 0.04813 O12 0.26300 0.00000 0.66960 1.00000 0.05319 O13 0.25500 0.00000 0.47620 1.00000 0.02153 O14 0.18100 0.00000 0.32310 1.00000 0.03800 O15 0.07300 0.29400 -0.09040 1.00000 0.05446 O16 0.45000 0.30200 -0.05930 1.00000 0.02153 O17 0.24500 0.00000 -0.04660 1.00000 0.01773 O-H1 0.25100 0.00000 0.85700 1.00000 0.02533 O-H2 0.05800 0.25800 0.35500 1.00000 0.04306 O-H3 0.24700 0.00000 0.41260 1.00000 0.04686 Wat1 0.24500 0.50000 0.62070 0.80000 0.02026 Wat2 0.29900 0.50000 0.79800 0.80000 0.02153 Wat3 0.21000 0.50000 0.49500 0.80000 0.01773 Wat4 0.35100 0.50000 0.69700 0.60000 0.05319 Wat5 0.44800 0.25900 0.04500 0.80000 0.02660 Wat6 0.44600 0.26100 0.22810 0.60000 0.03546 Wat7 0.44300 0.19800 0.37790 0.60000 0.07219