data_global _chemical_name_mineral 'Phengite-2M1' loop_ _publ_author_name 'Ivaldi G' 'Ferraris G' 'Curetti N' 'Compagnoni R' _journal_name_full 'European Journal of Mineralogy' _journal_volume 13 _journal_year 2001 _journal_page_first 1025 _journal_page_last 1034 _publ_section_title ; Coexisting 3T and 2M_1 polytypes of phengite from Cima Pal (Val Savenca, western Alps): Chemical and polytypic zoning and structural characterisation Sample: 2M1G ; _database_code_amcsd 0006915 _chemical_compound_source 'Cima Pal, Val Savenca, western Alps' _chemical_formula_sum 'K.99 Na.02 Al1.97 Mg.33 Fe.24 Ti.04 Si3.45 O12 H2' _cell_length_a 5.225 _cell_length_b 9.057 _cell_length_c 19.956 _cell_angle_alpha 90 _cell_angle_beta 95.73 _cell_angle_gamma 90 _cell_volume 939.656 _exptl_crystal_density_diffrn 2.874 _symmetry_space_group_name_H-M 'C 1 2/c 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' 'x,-y,1/2+z' '1/2+x,1/2-y,1/2+z' '-x,y,1/2-z' '1/2-x,1/2+y,1/2-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 KI 0.00000 0.09564 0.25000 0.99000 0.02540 NaI 0.00000 0.09564 0.25000 0.02000 0.02540 AlM2 0.24663 0.08226 0.00003 0.71000 0.00810 MgM2 0.24663 0.08226 0.00003 0.16500 0.00810 FeM2 0.24663 0.08226 0.00003 0.12000 0.00810 TiM2 0.24663 0.08226 0.00003 0.02000 0.00810 SiT1 0.46349 0.92899 0.13551 0.86250 0.00830 AlT1 0.46349 0.92899 0.13551 0.13750 0.00830 SiT2 0.45222 0.25859 0.13555 0.86250 0.00920 AlT2 0.45222 0.25859 0.13555 0.13750 0.00920 O1 0.44690 0.09340 0.16886 1.00000 0.01590 O2 0.23330 0.82790 0.16095 1.00000 0.01710 O3 0.23290 0.35520 0.16929 1.00000 0.01610 O4 0.45670 0.93860 0.05410 1.00000 0.01320 O5 0.39460 0.25150 0.05413 1.00000 0.01330 O6 0.45570 0.56460 0.05271 1.00000 0.01770 H 0.37800 0.62900 0.05800 1.00000 0.07000