data_global _chemical_name_mineral 'Muscovite' loop_ _publ_author_name 'Guggenheim S' 'Chang Y H' 'Koster van Groos A F' _journal_name_full 'American Mineralogist' _journal_volume 72 _journal_year 1987 _journal_page_first 537 _journal_page_last 550 _publ_section_title ; Muscovite dehydroxylation: High-temperature studies Sample: T = 20 deg C, from Panasqueira, Portugal ; _database_code_amcsd 0001078 _chemical_formula_sum 'K Al2.908 Si3.092 O11.88 (F.12 H1.88)' _cell_length_a 5.1579 _cell_length_b 8.950 _cell_length_c 20.071 _cell_angle_alpha 90 _cell_angle_beta 95.75 _cell_angle_gamma 90 _cell_volume 921.880 _exptl_crystal_density_diffrn 2.872 _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 K 0.00000 0.09890 0.25000 1.00000 Al 0.25090 0.08360 0.00002 1.00000 AlT1 0.46490 0.92970 0.13481 0.22700 SiT1 0.46490 0.92970 0.13481 0.77300 AlT2 0.45160 0.25840 0.13495 0.22700 SiT2 0.45160 0.25840 0.13495 0.77300 O1 0.41330 0.09240 0.16720 1.00000 O2 0.25210 0.80990 0.15690 1.00000 O3 0.25170 0.37120 0.16780 1.00000 O4 0.46180 0.94350 0.05320 1.00000 O5 0.38430 0.25200 0.05320 1.00000 O-H 0.45750 0.56180 0.04990 0.94000 F 0.45750 0.56180 0.04990 0.06000 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 K 0.02215 0.02516 0.02081 0.00000 0.00099 0.00000 Al 0.00640 0.00852 0.01091 -0.00093 -0.00036 0.00036 AlT1 0.00787 0.00893 0.01071 0.00000 -0.00021 0.00027 SiT1 0.00787 0.00893 0.01071 0.00000 -0.00021 0.00027 AlT2 0.00827 0.01055 0.01030 -0.00047 -0.00078 0.00000 SiT2 0.00827 0.01055 0.01030 -0.00047 -0.00078 0.00000 O1 0.02135 0.01461 0.01616 0.00070 0.00260 0.00091 O2 0.01441 0.02354 0.01758 -0.00489 -0.00260 0.00272 O3 0.01374 0.01988 0.01495 0.00465 -0.00156 -0.00272 O4 0.00761 0.01136 0.01232 0.00186 -0.00104 0.00181 O5 0.01081 0.01055 0.01051 0.00000 0.00000 0.00181 O-H 0.00974 0.01258 0.01273 -0.00093 0.00052 -0.00272 F 0.00974 0.01258 0.01273 -0.00093 0.00052 -0.00272