 
data_sl97 
 
_audit_creation_method            SHELXL-97 
_chemical_name_systematic 
; 
 ? 
; 
_chemical_name_common             ? 
_chemical_melting_point           ? 
_chemical_formula_moiety          ? 
_chemical_formula_sum 
 'Fe Mg O4 Si' 
_chemical_formula_weight          172.25 
 
loop_ 
 _atom_type_symbol 
 _atom_type_description 
 _atom_type_scat_dispersion_real 
 _atom_type_scat_dispersion_imag 
 _atom_type_scat_source 
 'Mg'  'Mg'   0.0486   0.0000 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 'Fe'  'Fe'   0.3463   0.0000 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 'Si'  'Si'   0.0817   0.0000 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 'O'  'O'   0.0106   0.0000 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 
_symmetry_cell_setting            ? 
_symmetry_space_group_name_H-M    ? 
 
loop_ 
 _symmetry_equiv_pos_as_xyz 
 'x, y, z' 
 'x+1/2, -y+1/2, -z+1/2' 
 '-x, y+1/2, -z' 
 '-x+1/2, -y, z+1/2' 
 '-x, -y, -z' 
 '-x-1/2, y-1/2, z-1/2' 
 'x, -y-1/2, z' 
 'x-1/2, y, -z-1/2' 
 
_cell_length_a                    10.2462(4) 
_cell_length_b                    6.0011(4) 
_cell_length_c                    4.7644(10) 
_cell_angle_alpha                 90.00 
_cell_angle_beta                  90.00 
_cell_angle_gamma                 90.00 
_cell_volume                      292.96(7) 
_cell_formula_units_Z             4 
_cell_measurement_temperature     293(2) 
_cell_measurement_reflns_used     ? 
_cell_measurement_theta_min       ? 
_cell_measurement_theta_max       ? 
 
_exptl_crystal_description        ? 
_exptl_crystal_colour             ? 
_exptl_crystal_size_max           ? 
_exptl_crystal_size_mid           ? 
_exptl_crystal_size_min           ? 
_exptl_crystal_density_meas       ? 
_exptl_crystal_density_diffrn     3.905 
_exptl_crystal_density_method     'not measured' 
_exptl_crystal_F_000              336 
_exptl_absorpt_coefficient_mu     5.591 
_exptl_absorpt_correction_type    ? 
_exptl_absorpt_correction_T_min   ? 
_exptl_absorpt_correction_T_max   ? 
_exptl_absorpt_process_details    ? 
 
_exptl_special_details 
; 
 ? 
; 
 
_diffrn_ambient_temperature       293(2) 
_diffrn_radiation_wavelength      0.71073 
_diffrn_radiation_type            MoK\a 
_diffrn_radiation_source          'fine-focus sealed tube' 
_diffrn_radiation_monochromator   graphite 
_diffrn_measurement_device_type   ? 
_diffrn_measurement_method        ? 
_diffrn_detector_area_resol_mean  ? 
_diffrn_standards_number          ? 
_diffrn_standards_interval_count  ? 
_diffrn_standards_interval_time   ? 
_diffrn_standards_decay_%         ? 
_diffrn_reflns_number             3301 
_diffrn_reflns_av_R_equivalents   0.0415 
_diffrn_reflns_av_sigmaI/netI     0.0213 
_diffrn_reflns_limit_h_min        -15 
_diffrn_reflns_limit_h_max        15 
_diffrn_reflns_limit_k_min        -7 
_diffrn_reflns_limit_k_max        7 
_diffrn_reflns_limit_l_min        -6 
_diffrn_reflns_limit_l_max        7 
_diffrn_reflns_theta_min          3.98 
_diffrn_reflns_theta_max          31.93 
_reflns_number_total              505 
_reflns_number_gt                 455 
_reflns_threshold_expression      >2sigma(I) 
 
_computing_data_collection        ? 
_computing_cell_refinement        ? 
_computing_data_reduction         ? 
_computing_structure_solution     'SHELXS-97 (Sheldrick, 1990)' 
_computing_structure_refinement   'SHELXL-97 (Sheldrick, 1997)' 
_computing_molecular_graphics     ? 
_computing_publication_material   ? 
 
_refine_special_details 
; 
 Refinement of F² against ALL reflections.  The weighted R-factor wR and 
 goodness of fit S are based on F², conventional R-factors R are based 
 on F, with F set to zero for negative F². The threshold expression of 
 F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is 
 not relevant to the choice of reflections for refinement.  R-factors based 
 on F² are statistically about twice as large as those based on F, and R- 
 factors based on ALL data will be even larger. 
; 
 
_refine_ls_structure_factor_coef  Fsqd  
_refine_ls_matrix_type            full 
_refine_ls_weighting_scheme       calc  
_refine_ls_weighting_details 
 'calc w=1/[σ²(Fo²)+(0.0388P)²+0.0000P] where P=(Fo²+2Fc²)/3' 
_atom_sites_solution_primary      direct 
_atom_sites_solution_secondary    difmap 
_atom_sites_solution_hydrogens    geom 
_refine_ls_hydrogen_treatment     mixed 
_refine_ls_extinction_method      none 
_refine_ls_extinction_coef        ? 
_refine_ls_number_reflns          505 
_refine_ls_number_parameters      42 
_refine_ls_number_restraints      0 
_refine_ls_R_factor_all           0.0288 
_refine_ls_R_factor_gt            0.0240 
_refine_ls_wR_factor_ref          0.0579 
_refine_ls_wR_factor_gt           0.0563 
_refine_ls_goodness_of_fit_ref    1.162 
_refine_ls_restrained_S_all       1.162 
_refine_ls_shift/su_max           0.000 
_refine_ls_shift/su_mean          0.000 
 
loop_ 
 _atom_site_label 
 _atom_site_type_symbol 
 _atom_site_fract_x 
 _atom_site_fract_y 
 _atom_site_fract_z 
 _atom_site_U_iso_or_equiv 
 _atom_site_adp_type 
 _atom_site_occupancy 
 _atom_site_symmetry_multiplicity 
 _atom_site_calc_flag 
 _atom_site_refinement_flags 
 _atom_site_disorder_assembly 
 _atom_site_disorder_group 
Fe1 Fe 0.5000 0.0000 0.5000 0.00402(19) Uani 0.140(4) 2 d SP . . 
Mg1 Mg 0.5000 0.0000 0.5000 0.00402(19) Uani 0.860(4) 2 d SP . . 
Fe2 Fe 0.22209(5) 0.2500 0.51090(10) 0.0045(2) Uani 0.138(4) 2 d SP . . 
Mg2 Mg 0.22209(5) 0.2500 0.51090(10) 0.0045(2) Uani 0.862(4) 2 d SP . . 
Si1 Si 0.40539(5) 0.2500 0.07328(9) 0.00377(15) Uani 1 2 d S . . 
O1 O 0.40830(12) 0.2500 -0.2658(3) 0.0055(3) Uani 1 2 d S . . 
O2 O 0.55196(12) 0.2500 0.2195(3) 0.0056(3) Uani 1 2 d S . . 
O3 O 0.33662(8) 0.46587(18) 0.22079(18) 0.0063(2) Uani 1 1 d . . . 
 
 
_geom_special_details 
; 
 All esds (except the esd in the dihedral angle between two l.s. planes) 
 are estimated using the full covariance matrix.  The cell esds are taken 
 into account individually in the estimation of esds in distances, angles 
 and torsion angles; correlations between esds in cell parameters are only 
 used when they are defined by crystal symmetry.  An approximate (isotropic) 
 treatment of cell esds is used for estimating esds involving l.s. planes. 
; 
 
loop_ 
 _geom_bond_atom_site_label_1 
 _geom_bond_atom_site_label_2 
 _geom_bond_distance 
 _geom_bond_site_symmetry_2 
 _geom_bond_publ_flag 
Fe1 O2 2.0784(9) 5_656 ? 
Fe1 O2 2.0784(9) . ? 
Fe1 O1 2.0926(9) 5_655 ? 
Fe1 O1 2.0926(9) 1_556 ? 
Fe1 O3 2.1480(9) 7_565 ? 
Fe1 O3 2.1480(9) 3_646 ? 
Fe1 Si1 2.7063(5) . ? 
Fe1 Si1 2.7063(5) 5_656 ? 
Fe1 Mg1 3.0006(2) 3_656 ? 
Fe1 Mg1 3.0006(2) 3_646 ? 
Fe1 Mg2 3.2190(4) 5_656 ? 
Fe2 O2 2.0601(13) 2_455 ? 
Fe2 O3 2.0662(11) 4_565 ? 
Fe2 O3 2.0662(11) 6_656 ? 
Fe2 O1 2.1846(13) 1_556 ? 
Fe2 O3 2.2284(10) 7_565 ? 
Fe2 O3 2.2284(10) . ? 
Fe2 Si1 2.8062(7) . ? 
Fe2 Mg1 3.2190(4) 3_656 ? 
Si1 O1 1.6157(13) . ? 
Si1 O3 1.6335(10) 7_565 ? 
Si1 O3 1.6335(10) . ? 
Si1 O2 1.6556(13) . ? 
Si1 Mg1 2.7063(5) 3_656 ? 
Si1 Fe1 2.7063(5) 3_656 ? 
Si1 Mg1 3.2636(6) 1_554 ? 
Si1 Mg1 3.2636(6) 3_655 ? 
O1 Mg1 2.0926(9) 1_554 ? 
O1 Fe1 2.0926(9) 1_554 ? 
O1 Mg1 2.0926(9) 3_655 ? 
O1 Fe1 2.0926(9) 3_655 ? 
O1 Mg2 2.1846(13) 1_554 ? 
O1 Fe2 2.1846(13) 1_554 ? 
O2 Mg2 2.0601(13) 2 ? 
O2 Fe2 2.0601(13) 2 ? 
O2 Mg1 2.0784(9) 3_656 ? 
O2 Fe1 2.0784(9) 3_656 ? 
O3 Mg2 2.0662(10) 6_665 ? 
O3 Fe2 2.0662(10) 6_665 ? 
O3 Mg1 2.1480(9) 3_656 ? 
O3 Fe1 2.1480(9) 3_656 ? 
 
loop_ 
 _geom_angle_atom_site_label_1 
 _geom_angle_atom_site_label_2 
 _geom_angle_atom_site_label_3 
 _geom_angle 
 _geom_angle_site_symmetry_1 
 _geom_angle_site_symmetry_3 
 _geom_angle_publ_flag 
O2 Fe1 O2 180.0 5_656 . ? 
O2 Fe1 O1 86.58(4) 5_656 5_655 ? 
O2 Fe1 O1 93.42(4) . 5_655 ? 
O2 Fe1 O1 93.42(4) 5_656 1_556 ? 
O2 Fe1 O1 86.58(4) . 1_556 ? 
O1 Fe1 O1 180.00(6) 5_655 1_556 ? 
O2 Fe1 O3 105.51(4) 5_656 7_565 ? 
O2 Fe1 O3 74.49(4) . 7_565 ? 
O1 Fe1 O3 95.05(4) 5_655 7_565 ? 
O1 Fe1 O3 84.95(4) 1_556 7_565 ? 
O2 Fe1 O3 74.49(4) 5_656 3_646 ? 
O2 Fe1 O3 105.51(4) . 3_646 ? 
O1 Fe1 O3 84.95(4) 5_655 3_646 ? 
O1 Fe1 O3 95.05(4) 1_556 3_646 ? 
O3 Fe1 O3 180.00(4) 7_565 3_646 ? 
O2 Fe1 Si1 142.32(3) 5_656 . ? 
O2 Fe1 Si1 37.68(3) . . ? 
O1 Fe1 Si1 99.07(3) 5_655 . ? 
O1 Fe1 Si1 80.93(3) 1_556 . ? 
O3 Fe1 Si1 37.13(3) 7_565 . ? 
O3 Fe1 Si1 142.87(3) 3_646 . ? 
O2 Fe1 Si1 37.68(3) 5_656 5_656 ? 
O2 Fe1 Si1 142.32(3) . 5_656 ? 
O1 Fe1 Si1 80.93(3) 5_655 5_656 ? 
O1 Fe1 Si1 99.07(3) 1_556 5_656 ? 
O3 Fe1 Si1 142.87(3) 7_565 5_656 ? 
O3 Fe1 Si1 37.13(3) 3_646 5_656 ? 
Si1 Fe1 Si1 180.0 . 5_656 ? 
O2 Fe1 Mg1 136.21(3) 5_656 3_656 ? 
O2 Fe1 Mg1 43.79(3) . 3_656 ? 
O1 Fe1 Mg1 135.80(2) 5_655 3_656 ? 
O1 Fe1 Mg1 44.20(2) 1_556 3_656 ? 
O3 Fe1 Mg1 84.53(3) 7_565 3_656 ? 
O3 Fe1 Mg1 95.47(3) 3_646 3_656 ? 
Si1 Fe1 Mg1 56.333(7) . 3_656 ? 
Si1 Fe1 Mg1 123.667(7) 5_656 3_656 ? 
O2 Fe1 Mg1 43.79(3) 5_656 3_646 ? 
O2 Fe1 Mg1 136.21(3) . 3_646 ? 
O1 Fe1 Mg1 44.20(2) 5_655 3_646 ? 
O1 Fe1 Mg1 135.80(2) 1_556 3_646 ? 
O3 Fe1 Mg1 95.47(3) 7_565 3_646 ? 
O3 Fe1 Mg1 84.53(3) 3_646 3_646 ? 
Si1 Fe1 Mg1 123.667(7) . 3_646 ? 
Si1 Fe1 Mg1 56.333(7) 5_656 3_646 ? 
Mg1 Fe1 Mg1 180.0 3_656 3_646 ? 
O2 Fe1 Mg2 84.29(3) 5_656 5_656 ? 
O2 Fe1 Mg2 95.71(3) . 5_656 ? 
O1 Fe1 Mg2 42.27(3) 5_655 5_656 ? 
O1 Fe1 Mg2 137.73(3) 1_556 5_656 ? 
O3 Fe1 Mg2 136.37(3) 7_565 5_656 ? 
O3 Fe1 Mg2 43.63(3) 3_646 5_656 ? 
Si1 Fe1 Mg2 124.272(13) . 5_656 ? 
Si1 Fe1 Mg2 55.728(13) 5_656 5_656 ? 
Mg1 Fe1 Mg2 117.780(4) 3_656 5_656 ? 
Mg1 Fe1 Mg2 62.220(4) 3_646 5_656 ? 
O2 Fe2 O3 90.66(3) 2_455 4_565 ? 
O2 Fe2 O3 90.66(3) 2_455 6_656 ? 
O3 Fe2 O3 111.23(6) 4_565 6_656 ? 
O2 Fe2 O1 176.94(5) 2_455 1_556 ? 
O3 Fe2 O1 91.06(3) 4_565 1_556 ? 
O3 Fe2 O1 91.06(3) 6_656 1_556 ? 
O2 Fe2 O3 96.61(4) 2_455 7_565 ? 
O3 Fe2 O3 158.95(5) 4_565 7_565 ? 
O3 Fe2 O3 88.50(2) 6_656 7_565 ? 
O1 Fe2 O3 80.92(4) 1_556 7_565 ? 
O2 Fe2 O3 96.61(4) 2_455 . ? 
O3 Fe2 O3 88.50(2) 4_565 . ? 
O3 Fe2 O3 158.95(5) 6_656 . ? 
O1 Fe2 O3 80.92(4) 1_556 . ? 
O3 Fe2 O3 71.09(6) 7_565 . ? 
O2 Fe2 Si1 99.81(4) 2_455 . ? 
O3 Fe2 Si1 123.67(3) 4_565 . ? 
O3 Fe2 Si1 123.67(3) 6_656 . ? 
O1 Fe2 Si1 77.14(4) 1_556 . ? 
O3 Fe2 Si1 35.58(3) 7_565 . ? 
O3 Fe2 Si1 35.58(3) . . ? 
O2 Fe2 Mg1 137.72(3) 2_455 3_656 ? 
O3 Fe2 Mg1 83.15(3) 4_565 3_656 ? 
O3 Fe2 Mg1 130.54(3) 6_656 3_656 ? 
O1 Fe2 Mg1 40.12(2) 1_556 3_656 ? 
O3 Fe2 Mg1 78.18(3) 7_565 3_656 ? 
O3 Fe2 Mg1 41.69(2) . 3_656 ? 
Si1 Fe2 Mg1 52.840(12) . 3_656 ? 
O1 Si1 O3 115.98(4) . 7_565 ? 
O1 Si1 O3 115.98(4) . . ? 
O3 Si1 O3 104.94(7) 7_565 . ? 
O1 Si1 O2 113.83(7) . . ? 
O3 Si1 O2 102.13(4) 7_565 . ? 
O3 Si1 O2 102.13(4) . . ? 
O1 Si1 Mg1 138.12(3) . 3_656 ? 
O3 Si1 Mg1 105.72(4) 7_565 3_656 ? 
O3 Si1 Mg1 52.53(3) . 3_656 ? 
O2 Si1 Mg1 50.12(3) . 3_656 ? 
O1 Si1 Fe1 138.12(3) . 3_656 ? 
O3 Si1 Fe1 105.72(4) 7_565 3_656 ? 
O3 Si1 Fe1 52.53(3) . 3_656 ? 
O2 Si1 Fe1 50.12(3) . 3_656 ? 
Mg1 Si1 Fe1 0.0 3_656 3_656 ? 
O1 Si1 Fe1 138.12(3) . . ? 
O3 Si1 Fe1 52.53(3) 7_565 . ? 
O3 Si1 Fe1 105.72(4) . . ? 
O2 Si1 Fe1 50.12(3) . . ? 
Mg1 Si1 Fe1 67.335(14) 3_656 . ? 
Fe1 Si1 Fe1 67.335(14) 3_656 . ? 
O1 Si1 Fe2 139.05(5) . . ? 
O3 Si1 Fe2 52.53(3) 7_565 . ? 
O3 Si1 Fe2 52.53(3) . . ? 
O2 Si1 Fe2 107.12(5) . . ? 
Mg1 Si1 Fe2 71.432(16) 3_656 . ? 
Fe1 Si1 Fe2 71.432(16) 3_656 . ? 
Fe1 Si1 Fe2 71.432(16) . . ? 
O1 Si1 Mg1 32.62(2) . 1_554 ? 
O3 Si1 Mg1 97.10(3) 7_565 1_554 ? 
O3 Si1 Mg1 148.51(4) . 1_554 ? 
O2 Si1 Mg1 94.75(4) . 1_554 ? 
Mg1 Si1 Mg1 141.003(18) 3_656 1_554 ? 
Fe1 Si1 Mg1 141.003(18) 3_656 1_554 ? 
Fe1 Si1 Mg1 105.514(14) . 1_554 ? 
Fe2 Si1 Mg1 145.149(13) . 1_554 ? 
O1 Si1 Mg1 32.62(2) . 3_655 ? 
O3 Si1 Mg1 148.51(4) 7_565 3_655 ? 
O3 Si1 Mg1 97.10(3) . 3_655 ? 
O2 Si1 Mg1 94.75(4) . 3_655 ? 
Mg1 Si1 Mg1 105.514(14) 3_656 3_655 ? 
Fe1 Si1 Mg1 105.514(14) 3_656 3_655 ? 
Fe1 Si1 Mg1 141.003(18) . 3_655 ? 
Fe2 Si1 Mg1 145.149(13) . 3_655 ? 
Mg1 Si1 Mg1 54.736(12) 1_554 3_655 ? 
Si1 O1 Mg1 122.79(4) . 1_554 ? 
Si1 O1 Fe1 122.79(4) . 1_554 ? 
Mg1 O1 Fe1 0.0 1_554 1_554 ? 
Si1 O1 Mg1 122.79(4) . 3_655 ? 
Mg1 O1 Mg1 91.61(5) 1_554 3_655 ? 
Fe1 O1 Mg1 91.61(5) 1_554 3_655 ? 
Si1 O1 Fe1 122.79(4) . 3_655 ? 
Mg1 O1 Fe1 91.61(5) 1_554 3_655 ? 
Fe1 O1 Fe1 91.61(5) 1_554 3_655 ? 
Mg1 O1 Fe1 0.0 3_655 3_655 ? 
Si1 O1 Mg2 118.09(7) . 1_554 ? 
Mg1 O1 Mg2 97.61(4) 1_554 1_554 ? 
Fe1 O1 Mg2 97.61(4) 1_554 1_554 ? 
Mg1 O1 Mg2 97.61(4) 3_655 1_554 ? 
Fe1 O1 Mg2 97.61(4) 3_655 1_554 ? 
Si1 O1 Fe2 118.09(7) . 1_554 ? 
Mg1 O1 Fe2 97.61(4) 1_554 1_554 ? 
Fe1 O1 Fe2 97.61(4) 1_554 1_554 ? 
Mg1 O1 Fe2 97.61(4) 3_655 1_554 ? 
Fe1 O1 Fe2 97.61(4) 3_655 1_554 ? 
Mg2 O1 Fe2 0.00(3) 1_554 1_554 ? 
Si1 O2 Mg2 122.90(7) . 2 ? 
Si1 O2 Fe2 122.90(7) . 2 ? 
Mg2 O2 Fe2 0.00(3) 2 2 ? 
Si1 O2 Mg1 92.19(5) . 3_656 ? 
Mg2 O2 Mg1 124.01(4) 2 3_656 ? 
Fe2 O2 Mg1 124.01(4) 2 3_656 ? 
Si1 O2 Fe1 92.19(5) . 3_656 ? 
Mg2 O2 Fe1 124.01(4) 2 3_656 ? 
Fe2 O2 Fe1 124.01(4) 2 3_656 ? 
Mg1 O2 Fe1 0.0 3_656 3_656 ? 
Si1 O2 Fe1 92.19(5) . . ? 
Mg2 O2 Fe1 124.01(4) 2 . ? 
Fe2 O2 Fe1 124.01(4) 2 . ? 
Mg1 O2 Fe1 92.41(5) 3_656 . ? 
Fe1 O2 Fe1 92.41(5) 3_656 . ? 
Si1 O3 Mg2 124.88(5) . 6_665 ? 
Si1 O3 Fe2 124.88(5) . 6_665 ? 
Mg2 O3 Fe2 0.00(3) 6_665 6_665 ? 
Si1 O3 Mg1 90.34(4) . 3_656 ? 
Mg2 O3 Mg1 116.61(5) 6_665 3_656 ? 
Fe2 O3 Mg1 116.61(5) 6_665 3_656 ? 
Si1 O3 Fe1 90.34(4) . 3_656 ? 
Mg2 O3 Fe1 116.61(5) 6_665 3_656 ? 
Fe2 O3 Fe1 116.61(5) 6_665 3_656 ? 
Mg1 O3 Fe1 0.0 3_656 3_656 ? 
Si1 O3 Fe2 91.89(5) . . ? 
Mg2 O3 Fe2 128.80(4) 6_665 . ? 
Fe2 O3 Fe2 128.80(4) 6_665 . ? 
Mg1 O3 Fe2 94.69(4) 3_656 . ? 
Fe1 O3 Fe2 94.69(4) 3_656 . ? 
 
_diffrn_measured_fraction_theta_max    0.923 
_diffrn_reflns_theta_full              31.93 
_diffrn_measured_fraction_theta_full   0.923 
_refine_diff_density_max    0.525 
_refine_diff_density_min   -0.754 
_refine_diff_density_rms    0.175 
