data_global _chemical_name_mineral 'Lawsonite' loop_ _publ_author_name 'Meyer H W' 'Marion S' 'Sondergeld P' 'Carpenter M A' 'Knight K S' 'Redfern S A T' 'Dove M T' _journal_name_full 'American Mineralogist' _journal_volume 86 _journal_year 2001 _journal_page_first 566 _journal_page_last 577 _publ_section_title ; Displacive components of the low-temperature phase transitions in lawsonite T = 268 K ; _database_code_amcsd 0002638 _chemical_formula_sum 'Ca (Al1.94 Fe.06) Si2 O10 D4' _cell_length_a 5.85539 _cell_length_b 8.79152 _cell_length_c 13.1326 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 676.037 _exptl_crystal_density_diffrn 3.144 _symmetry_space_group_name_H-M 'P m c n' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-x,y,z' '1/2+x,-y,-z' '1/2+x,1/2+y,1/2-z' '1/2-x,1/2-y,1/2+z' 'x,1/2-y,1/2+z' '-x,1/2+y,1/2-z' '-x,-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 Ca -0.25000 0.08030 0.24710 1.00000 0.00920 Al 0.00000 0.00000 0.00000 0.97000 0.00400 Fe 0.00000 0.00000 0.00000 0.03000 0.00400 Ala 0.00000 0.00000 0.50000 0.97000 0.00400 Fea 0.00000 0.00000 0.50000 0.03000 0.00400 Si -0.25000 0.73100 0.13120 1.00000 0.00370 Sia -0.25000 0.72900 0.36640 1.00000 0.00370 O1 -0.25000 -0.20340 0.25100 1.00000 0.00680 O2 0.02100 0.12700 0.11790 1.00000 0.00500 O2a 0.02400 0.12890 0.38420 1.00000 0.00500 O3 -0.25000 -0.11350 0.06610 1.00000 0.00340 O3a -0.25000 -0.11160 0.43330 1.00000 0.00340 O4 -0.25000 0.39360 0.05160 1.00000 0.00760 O4a -0.25000 0.38680 0.45770 1.00000 0.00760 O5 -0.25000 0.35990 0.24900 1.00000 0.02200 Dw -0.25000 0.40700 0.18050 1.00000 0.05700 Dwa -0.25000 0.42000 0.30150 1.00000 0.06400 Dd -0.25000 0.27810 0.03830 1.00000 0.03600 Dda -0.25000 0.30700 0.41780 1.00000 0.05200