 
data_ig_ht_month_25_0m 
 
_audit_creation_method            SHELXL-97 
_chemical_name_systematic 
; 
 ? 
; 
_chemical_name_common             ? 
_chemical_melting_point           ? 
_chemical_formula_moiety          ? 
_chemical_formula_sum 
 'Al2 Ca O21 Si6' 
_chemical_formula_weight          598.58 
 
loop_ 
 _atom_type_symbol 
 _atom_type_description 
 _atom_type_scat_dispersion_real 
 _atom_type_scat_dispersion_imag 
 _atom_type_scat_source 
 'O'  'O'   0.0106   0.0060 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 'Al'  'Al'   0.0645   0.0514 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 'Si'  'Si'   0.0817   0.0704 
 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 
 'Ca'  'Ca'   0.2262   0.3064 
 '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, y+1/2, -z' 
 
_cell_length_a                    7.2989(2) 
_cell_length_b                    17.3509(4) 
_cell_length_c                    7.4288(2) 
_cell_angle_alpha                 90.00 
_cell_angle_beta                  105.7550(10) 
_cell_angle_gamma                 90.00 
_cell_volume                      905.46(4) 
_cell_formula_units_Z             2 
_cell_measurement_temperature     296(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     2.196 
_exptl_crystal_density_method     'not measured' 
_exptl_crystal_F_000              596 
_exptl_absorpt_coefficient_mu     0.948 
_exptl_absorpt_correction_type    ? 
_exptl_absorpt_correction_T_min   ? 
_exptl_absorpt_correction_T_max   ? 
_exptl_absorpt_process_details    ? 
 
_exptl_special_details 
; 
 ? 
; 
 
_diffrn_ambient_temperature       296(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_reflns_number             8610 
_diffrn_reflns_av_R_equivalents   0.0290 
_diffrn_reflns_av_sigmaI/netI     0.0319 
_diffrn_reflns_limit_h_min        -7 
_diffrn_reflns_limit_h_max        8 
_diffrn_reflns_limit_k_min        -19 
_diffrn_reflns_limit_k_max        19 
_diffrn_reflns_limit_l_min        -8 
_diffrn_reflns_limit_l_max        8 
_diffrn_reflns_theta_min          2.35 
_diffrn_reflns_theta_max          23.63 
_reflns_number_total              2667 
_reflns_number_gt                 2561 
_reflns_threshold_expression      >2sigma(I) 
 
_computing_data_collection        ? 
_computing_cell_refinement        ? 
_computing_data_reduction         ? 
_computing_structure_solution     'SHELXS-97 (Sheldrick, 2008)' 
_computing_structure_refinement   'SHELXL-97 (Sheldrick, 2008)' 
_computing_molecular_graphics     ? 
_computing_publication_material   ? 
 
_refine_special_details 
; 
 Refinement of F^2^ against ALL reflections.  The weighted R-factor wR and 
 goodness of fit S are based on F^2^, conventional R-factors R are based 
 on F, with F set to zero for negative F^2^. The threshold expression of 
 F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is 
 not relevant to the choice of reflections for refinement.  R-factors based 
 on F^2^ 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/[\s^2^(Fo^2^)+(0.0413P)^2^+2.0145P] where P=(Fo^2^+2Fc^2^)/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_abs_structure_details 
 'Flack H D (1983), Acta Cryst. A39, 876-881' 
_refine_ls_abs_structure_Flack    0.11(7) 
_refine_ls_number_reflns          2667 
_refine_ls_number_parameters      271 
_refine_ls_number_restraints      1 
_refine_ls_R_factor_all           0.0356 
_refine_ls_R_factor_gt            0.0337 
_refine_ls_wR_factor_ref          0.0877 
_refine_ls_wR_factor_gt           0.0868 
_refine_ls_goodness_of_fit_ref    1.111 
_refine_ls_restrained_S_all       1.111 
_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 
Ca1 Ca 0.69393(17) 0.25185(8) 0.15644(18) 0.0284(3) Uani 1 1 d . . . 
Si1 Si 0.3608(2) 0.46584(8) 0.6057(2) 0.0159(4) Uani 1 1 d . . . 
Si2 Si 0.3308(2) 0.13553(9) 0.5908(2) 0.0153(3) Uani 1 1 d . . . 
Si3 Si 0.0233(2) 0.26365(9) 0.5211(2) 0.0145(3) Uani 1 1 d . . . 
Si4 Si 0.1272(2) 0.05052(9) 0.8389(2) 0.0164(3) Uani 1 1 d . . . 
Si5 Si 0.1014(2) 0.39376(9) 0.8187(2) 0.0157(3) Uani 1 1 d . . . 
Si6 Si 0.2237(2) 0.01866(9) 0.2608(2) 0.0156(3) Uani 1 1 d . . . 
Al1 Al 0.7609(2) 0.12620(9) 0.5697(2) 0.0149(4) Uani 1 1 d . . . 
Al2 Al 0.0875(2) 0.39449(9) 0.2466(2) 0.0154(4) Uani 1 1 d . . . 
O1 O 0.7158(6) 0.0529(2) 0.4050(6) 0.0239(9) Uani 1 1 d . . . 
O2 O 0.5536(5) 0.1508(2) 0.6245(6) 0.0222(10) Uani 1 1 d . . . 
O3 O 0.8414(5) 0.2064(2) 0.4704(5) 0.0178(9) Uani 1 1 d . . . 
O4 O 0.9370(5) 0.1011(2) 0.7677(6) 0.0228(9) Uani 1 1 d . . . 
O5 O 0.2969(6) 0.4180(2) 0.7675(6) 0.0215(9) Uani 1 1 d . . . 
O6 O 0.2951(6) 0.4228(2) 0.4087(6) 0.0226(9) Uani 1 1 d . . . 
O7 O 0.5901(5) 0.4647(2) 0.6732(6) 0.0249(9) Uani 1 1 d . . . 
O8 O 0.2228(6) 0.2175(2) 0.5796(6) 0.0249(9) Uani 1 1 d . . . 
O9 O 0.2999(6) 0.0854(3) 0.7636(6) 0.0263(10) Uani 1 1 d . . . 
O10 O 0.2332(6) 0.0885(3) 0.4034(6) 0.0309(10) Uani 1 1 d . . . 
O11 O 0.0159(6) 0.3177(2) 0.6983(6) 0.0243(10) Uani 1 1 d . . . 
O12 O 1.0009(5) 0.3129(2) 0.3335(5) 0.0187(9) Uani 1 1 d . . . 
O13 O 0.9083(5) 0.4621(2) 0.2187(6) 0.0261(10) Uani 1 1 d . . . 
O14 O 0.2088(6) 0.0589(2) 0.0637(6) 0.0273(10) Uani 1 1 d . . . 
O15 O 0.1366(6) 0.3746(2) 0.0353(6) 0.0248(10) Uani 1 1 d . . . 
O16 O 0.9578(6) 0.4652(3) 0.7520(6) 0.0303(10) Uani 1 1 d . . . 
W1 O 0.3719(8) 0.2241(4) 0.1481(9) 0.0635(16) Uani 1 1 d . . . 
W2 O 0.6058(9) 0.3001(4) 0.8545(8) 0.0641(17) Uani 1 1 d . . . 
W3 O 0.6696(11) 0.1198(3) 0.0655(8) 0.074(2) Uani 1 1 d . . . 
W4 O 0.9500(9) 0.2180(4) 0.0128(9) 0.0677(17) Uani 1 1 d . . . 
W5 O 0.6026(7) 0.3723(3) 0.2555(9) 0.0531(15) Uani 1 1 d . . . 
 
loop_ 
 _atom_site_aniso_label 
 _atom_site_aniso_U_11 
 _atom_site_aniso_U_22 
 _atom_site_aniso_U_33 
 _atom_site_aniso_U_23 
 _atom_site_aniso_U_13 
 _atom_site_aniso_U_12 
Ca1 0.0267(6) 0.0275(7) 0.0272(7) 0.0048(6) 0.0009(5) -0.0054(5) 
Si1 0.0160(8) 0.0156(9) 0.0160(8) 0.0027(7) 0.0044(6) -0.0018(6) 
Si2 0.0133(7) 0.0160(8) 0.0176(8) 0.0009(7) 0.0058(6) 0.0005(6) 
Si3 0.0147(7) 0.0129(7) 0.0169(8) -0.0001(7) 0.0059(6) -0.0010(6) 
Si4 0.0144(8) 0.0174(8) 0.0177(8) 0.0022(7) 0.0049(6) -0.0012(6) 
Si5 0.0179(7) 0.0137(8) 0.0171(8) -0.0002(7) 0.0075(6) 0.0014(6) 
Si6 0.0142(7) 0.0159(8) 0.0170(8) -0.0013(7) 0.0048(6) -0.0001(6) 
Al1 0.0139(8) 0.0132(8) 0.0186(9) 0.0008(7) 0.0060(7) -0.0019(7) 
Al2 0.0152(8) 0.0153(9) 0.0158(9) 0.0014(7) 0.0044(7) -0.0002(7) 
O1 0.029(2) 0.017(2) 0.026(2) -0.0049(19) 0.0090(18) -0.0046(18) 
O2 0.016(2) 0.024(2) 0.028(2) 0.0012(19) 0.0089(18) 0.0000(17) 
O3 0.017(2) 0.016(2) 0.021(2) 0.0001(16) 0.0057(17) -0.0051(15) 
O4 0.021(2) 0.017(2) 0.029(2) 0.0007(18) 0.0046(18) 0.0011(17) 
O5 0.020(2) 0.024(2) 0.024(2) 0.0083(18) 0.0101(18) 0.0027(17) 
O6 0.021(2) 0.025(2) 0.021(2) -0.0007(18) 0.0043(18) -0.0049(17) 
O7 0.017(2) 0.024(2) 0.033(3) -0.005(2) 0.0063(18) -0.0056(18) 
O8 0.021(2) 0.019(2) 0.035(2) 0.000(2) 0.0074(18) 0.0069(18) 
O9 0.022(2) 0.030(2) 0.032(3) 0.010(2) 0.015(2) -0.0011(18) 
O10 0.029(2) 0.033(3) 0.030(3) -0.015(2) 0.006(2) 0.002(2) 
O11 0.028(2) 0.019(2) 0.028(2) -0.0094(19) 0.0124(18) -0.0044(17) 
O12 0.017(2) 0.018(2) 0.021(2) 0.0060(18) 0.0048(17) -0.0042(16) 
O13 0.021(2) 0.018(2) 0.040(3) 0.004(2) 0.0091(19) 0.0023(19) 
O14 0.032(2) 0.027(2) 0.022(2) 0.003(2) 0.0060(19) -0.0020(19) 
O15 0.026(2) 0.026(2) 0.024(2) 0.0004(19) 0.0095(18) -0.0084(19) 
O16 0.021(2) 0.031(3) 0.041(3) 0.006(2) 0.0116(19) 0.014(2) 
W1 0.041(3) 0.065(4) 0.089(4) -0.004(4) 0.026(3) -0.013(3) 
W2 0.094(5) 0.053(3) 0.040(3) 0.007(3) 0.010(3) 0.016(3) 
W3 0.137(6) 0.043(3) 0.043(3) 0.005(3) 0.025(4) 0.025(4) 
W4 0.068(4) 0.062(4) 0.079(4) -0.010(4) 0.030(3) -0.002(3) 
W5 0.043(3) 0.033(3) 0.091(4) -0.015(3) 0.031(3) -0.003(2) 
 
_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 
Ca1 W2 2.316(6) 1_554 ? 
Ca1 W5 2.371(5) . ? 
Ca1 W3 2.382(6) . ? 
Ca1 W1 2.383(5) . ? 
Ca1 O3 2.420(4) . ? 
Ca1 W4 2.462(6) . ? 
Ca1 O12 2.504(4) . ? 
Ca1 Si3 3.1018(19) 1_655 ? 
Ca1 Al1 3.688(2) . ? 
Ca1 Al2 3.713(2) 1_655 ? 
Si1 O6 1.596(4) . ? 
Si1 O1 1.606(4) 2_656 ? 
Si1 O7 1.612(4) . ? 
Si1 O5 1.630(4) . ? 
Si2 O2 1.599(4) . ? 
Si2 O10 1.604(5) . ? 
Si2 O9 1.616(4) . ? 
Si2 O8 1.618(4) . ? 
Si3 O12 1.605(4) 1_455 ? 
Si3 O8 1.614(4) . ? 
Si3 O3 1.619(4) 1_455 ? 
Si3 O11 1.629(4) . ? 
Si3 Ca1 3.1018(19) 1_455 ? 
Si4 O13 1.595(4) 2_646 ? 
Si4 O4 1.606(4) 1_455 ? 
Si4 O14 1.620(5) 1_556 ? 
Si4 O9 1.628(4) . ? 
Si5 O15 1.594(4) 1_556 ? 
Si5 O16 1.612(4) 1_455 ? 
Si5 O11 1.621(4) . ? 
Si5 O5 1.628(4) . ? 
Si6 O10 1.598(5) . ? 
Si6 O16 1.598(4) 2_646 ? 
Si6 O14 1.599(4) . ? 
Si6 O7 1.614(4) 2_646 ? 
Al1 O2 1.724(4) . ? 
Al1 O4 1.725(4) . ? 
Al1 O1 1.733(4) . ? 
Al1 O3 1.749(4) . ? 
Al2 O13 1.727(4) 1_455 ? 
Al2 O6 1.731(4) . ? 
Al2 O15 1.737(4) . ? 
Al2 O12 1.744(4) 1_455 ? 
Al2 Ca1 3.713(2) 1_455 ? 
O1 Si1 1.606(4) 2_646 ? 
O3 Si3 1.619(4) 1_655 ? 
O4 Si4 1.606(4) 1_655 ? 
O7 Si6 1.614(4) 2_656 ? 
O12 Si3 1.605(4) 1_655 ? 
O12 Al2 1.744(4) 1_655 ? 
O13 Si4 1.595(4) 2_656 ? 
O13 Al2 1.727(4) 1_655 ? 
O14 Si4 1.620(5) 1_554 ? 
O15 Si5 1.594(4) 1_554 ? 
O16 Si6 1.598(4) 2_656 ? 
O16 Si5 1.612(4) 1_655 ? 
W2 Ca1 2.316(6) 1_556 ? 
 
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 
W2 Ca1 W5 87.4(2) 1_554 . ? 
W2 Ca1 W3 95.4(2) 1_554 . ? 
W5 Ca1 W3 158.5(2) . . ? 
W2 Ca1 W1 92.0(2) 1_554 . ? 
W5 Ca1 W1 80.1(2) . . ? 
W3 Ca1 W1 78.5(3) . . ? 
W2 Ca1 O3 170.1(2) 1_554 . ? 
W5 Ca1 O3 94.41(19) . . ? 
W3 Ca1 O3 86.51(17) . . ? 
W1 Ca1 O3 97.85(19) . . ? 
W2 Ca1 W4 73.2(2) 1_554 . ? 
W5 Ca1 W4 130.94(19) . . ? 
W3 Ca1 W4 69.8(2) . . ? 
W1 Ca1 W4 143.1(2) . . ? 
O3 Ca1 W4 98.56(18) . . ? 
W2 Ca1 O12 109.2(2) 1_554 . ? 
W5 Ca1 O12 75.56(16) . . ? 
W3 Ca1 O12 122.9(2) . . ? 
W1 Ca1 O12 146.56(19) . . ? 
O3 Ca1 O12 62.07(12) . . ? 
W4 Ca1 O12 69.65(17) . . ? 
W2 Ca1 Si3 140.14(18) 1_554 1_655 ? 
W5 Ca1 Si3 83.52(16) . 1_655 ? 
W3 Ca1 Si3 106.95(17) . 1_655 ? 
W1 Ca1 Si3 124.13(17) . 1_655 ? 
O3 Ca1 Si3 31.08(9) . 1_655 ? 
W4 Ca1 Si3 83.95(15) . 1_655 ? 
O12 Ca1 Si3 31.00(9) . 1_655 ? 
W2 Ca1 Al1 163.57(18) 1_554 . ? 
W5 Ca1 Al1 104.33(16) . . ? 
W3 Ca1 Al1 69.52(15) . . ? 
W1 Ca1 Al1 79.00(16) . . ? 
O3 Ca1 Al1 23.27(9) . . ? 
W4 Ca1 Al1 105.98(16) . . ? 
O12 Ca1 Al1 85.15(9) . . ? 
Si3 Ca1 Al1 54.26(4) 1_655 . ? 
W2 Ca1 Al2 86.08(18) 1_554 1_655 ? 
W5 Ca1 Al2 67.99(13) . 1_655 ? 
W3 Ca1 Al2 133.4(2) . 1_655 ? 
W1 Ca1 Al2 148.08(17) . 1_655 ? 
O3 Ca1 Al2 85.62(10) . 1_655 ? 
W4 Ca1 Al2 66.15(15) . 1_655 ? 
O12 Ca1 Al2 23.80(9) . 1_655 ? 
Si3 Ca1 Al2 54.56(4) 1_655 1_655 ? 
Al1 Ca1 Al2 108.82(5) . 1_655 ? 
O6 Si1 O1 112.4(2) . 2_656 ? 
O6 Si1 O7 107.9(2) . . ? 
O1 Si1 O7 110.2(2) 2_656 . ? 
O6 Si1 O5 111.3(2) . . ? 
O1 Si1 O5 110.5(2) 2_656 . ? 
O7 Si1 O5 104.2(2) . . ? 
O2 Si2 O10 114.4(2) . . ? 
O2 Si2 O9 108.7(2) . . ? 
O10 Si2 O9 106.9(2) . . ? 
O2 Si2 O8 108.8(2) . . ? 
O10 Si2 O8 107.9(2) . . ? 
O9 Si2 O8 110.0(2) . . ? 
O12 Si3 O8 111.7(2) 1_455 . ? 
O12 Si3 O3 104.0(2) 1_455 1_455 ? 
O8 Si3 O3 112.4(2) . 1_455 ? 
O12 Si3 O11 112.2(2) 1_455 . ? 
O8 Si3 O11 107.0(2) . . ? 
O3 Si3 O11 109.6(2) 1_455 . ? 
O12 Si3 Ca1 53.48(14) 1_455 1_455 ? 
O8 Si3 Ca1 129.13(16) . 1_455 ? 
O3 Si3 Ca1 50.53(15) 1_455 1_455 ? 
O11 Si3 Ca1 123.77(16) . 1_455 ? 
O13 Si4 O4 112.0(2) 2_646 1_455 ? 
O13 Si4 O14 110.5(2) 2_646 1_556 ? 
O4 Si4 O14 109.5(2) 1_455 1_556 ? 
O13 Si4 O9 110.5(2) 2_646 . ? 
O4 Si4 O9 111.4(2) 1_455 . ? 
O14 Si4 O9 102.6(2) 1_556 . ? 
O15 Si5 O16 112.5(2) 1_556 1_455 ? 
O15 Si5 O11 108.7(2) 1_556 . ? 
O16 Si5 O11 109.6(2) 1_455 . ? 
O15 Si5 O5 112.2(2) 1_556 . ? 
O16 Si5 O5 105.5(2) 1_455 . ? 
O11 Si5 O5 108.2(2) . . ? 
O10 Si6 O16 111.4(2) . 2_646 ? 
O10 Si6 O14 104.8(3) . . ? 
O16 Si6 O14 110.5(2) 2_646 . ? 
O10 Si6 O7 110.9(2) . 2_646 ? 
O16 Si6 O7 107.3(2) 2_646 2_646 ? 
O14 Si6 O7 112.0(2) . 2_646 ? 
O2 Al1 O4 111.1(2) . . ? 
O2 Al1 O1 109.7(2) . . ? 
O4 Al1 O1 111.8(2) . . ? 
O2 Al1 O3 108.61(19) . . ? 
O4 Al1 O3 107.6(2) . . ? 
O1 Al1 O3 107.9(2) . . ? 
O2 Al1 Ca1 97.10(14) . . ? 
O4 Al1 Ca1 139.33(15) . . ? 
O1 Al1 Ca1 83.62(15) . . ? 
O3 Al1 Ca1 33.14(13) . . ? 
O13 Al2 O6 112.5(2) 1_455 . ? 
O13 Al2 O15 111.2(2) 1_455 . ? 
O6 Al2 O15 109.2(2) . . ? 
O13 Al2 O12 104.86(19) 1_455 1_455 ? 
O6 Al2 O12 108.1(2) . 1_455 ? 
O15 Al2 O12 111.0(2) . 1_455 ? 
O13 Al2 Ca1 84.67(15) 1_455 1_455 ? 
O6 Al2 Ca1 143.42(15) . 1_455 ? 
O15 Al2 Ca1 92.52(14) . 1_455 ? 
O12 Al2 Ca1 35.42(13) 1_455 1_455 ? 
Si1 O1 Al1 136.2(3) 2_646 . ? 
Si2 O2 Al1 147.4(3) . . ? 
Si3 O3 Al1 137.6(3) 1_655 . ? 
Si3 O3 Ca1 98.39(18) 1_655 . ? 
Al1 O3 Ca1 123.60(19) . . ? 
Si4 O4 Al1 142.7(3) 1_655 . ? 
Si5 O5 Si1 138.4(3) . . ? 
Si1 O6 Al2 139.4(3) . . ? 
Si1 O7 Si6 143.6(3) . 2_656 ? 
Si3 O8 Si2 147.2(3) . . ? 
Si2 O9 Si4 139.5(3) . . ? 
Si6 O10 Si2 152.9(3) . . ? 
Si5 O11 Si3 145.3(3) . . ? 
Si3 O12 Al2 142.4(2) 1_655 1_655 ? 
Si3 O12 Ca1 95.51(17) 1_655 . ? 
Al2 O12 Ca1 120.79(19) 1_655 . ? 
Si4 O13 Al2 138.4(3) 2_656 1_655 ? 
Si6 O14 Si4 145.0(3) . 1_554 ? 
Si5 O15 Al2 148.7(3) 1_554 . ? 
Si6 O16 Si5 157.5(3) 2_656 1_655 ? 
 
_diffrn_measured_fraction_theta_max    0.999 
_diffrn_reflns_theta_full              23.63 
_diffrn_measured_fraction_theta_full   0.999 
_refine_diff_density_max    0.626 
_refine_diff_density_min   -0.390 
_refine_diff_density_rms    0.090 
