#------------------------------------------------------------------------------ #$Date: 2025-02-21 04:59:15 +0200 (Fri, 21 Feb 2025) $ #$Revision: 297815 $ #$URL: file:///home/coder/svn-repositories/cod/cif/2/31/27/2312757.cif $ #------------------------------------------------------------------------------ # # This file is available in the Crystallography Open Database (COD), # http://www.crystallography.net/. The original data for this entry # were provided by IUCr Journals, http://journals.iucr.org/. # # The file may be used within the scientific community so long as # proper attribution is given to the journal article from which the # data were obtained. # data_2312757 loop_ _publ_author_name 'Kahlenberg, Volker' _publ_section_title ; Rb2Ca2Si2O7: a new alkali alkaline-earth silicate based on [Si2O7]6- anions. ; _journal_coeditor_code EF3065 _journal_issue 3 _journal_name_full 'Acta crystallographica. Section C, Structural chemistry' _journal_paper_doi 10.1107/S2053229625001196 _journal_volume 81 _journal_year 2025 _chemical_formula_iupac 'Rb2 Ca2 Si2 O7' _chemical_formula_sum 'Ca2 O7 Rb2 Si2' _chemical_formula_weight 419.28 _chemical_name_systematic ; Dirubidium dicalcium pyrosilicate ; _space_group_IT_number 59 _space_group_name_Hall '-P 2ab 2a' _space_group_name_H-M_alt 'P m m n :2' _symmetry_cell_setting orthorhombic _symmetry_space_group_name_H-M 'P m m n :2' _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _audit_conform_dict_name cif_core.dic _audit_conform_dict_version 2.4.3 _audit_creation_method 'WinGX routine CIF_UPDATE' _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_formula_units_Z 4 _cell_length_a 5.7363(6) _cell_length_b 13.8532(12) _cell_length_c 9.9330(10) _cell_measurement_reflns_used 2256 _cell_measurement_temperature 288(2) _cell_measurement_theta_max 29.495 _cell_measurement_theta_min 5.002 _cell_volume 789.34(13) _computing_cell_refinement ; CrysAlis PRO (Rigaku OD, 2020) ; _computing_data_collection ; CrysAlis PRO (Rigaku OD, 2020) ; _computing_data_reduction ; CrysAlis PRO (Rigaku OD, 2020) ; _computing_structure_refinement ; SHELXL97 (Sheldrick, 2008) ; _computing_structure_solution ; SIR2002 (Burla et al., 2003) ; _diffrn_ambient_temperature 288(2) _diffrn_detector 'CCD plate' _diffrn_detector_area_resol_mean 10.3575 _diffrn_measured_fraction_theta_full 0.997 _diffrn_measured_fraction_theta_max 0.997 _diffrn_measurement_device 'four-circle diffractometer' _diffrn_measurement_device_type 'Xcalibur, Ruby, Gemini ultra' _diffrn_measurement_method '\w scans' _diffrn_radiation_monochromator graphite _diffrn_radiation_probe x-ray _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_reflns_av_R_equivalents 0.0584 _diffrn_reflns_av_unetI/netI 0.0232 _diffrn_reflns_limit_h_max 7 _diffrn_reflns_limit_h_min -7 _diffrn_reflns_limit_k_max 17 _diffrn_reflns_limit_k_min -17 _diffrn_reflns_limit_l_max 12 _diffrn_reflns_limit_l_min -12 _diffrn_reflns_number 10834 _diffrn_reflns_theta_full 26.35 _diffrn_reflns_theta_max 26.35 _diffrn_reflns_theta_min 3.59 _diffrn_source 'fine-focus sealed X-ray tube' _exptl_absorpt_coefficient_mu 14 _exptl_absorpt_correction_T_max 0.678 _exptl_absorpt_correction_T_min 0.121 _exptl_absorpt_correction_type analytical _exptl_absorpt_process_details ; [CrysAlis PRO (Rigaku OD, 2020), based on expressions derived by Clark & Reid (1995)] ; _exptl_crystal_colour colourless _exptl_crystal_density_diffrn 3.528 _exptl_crystal_density_method 'not measured' _exptl_crystal_description 'thin plate' _exptl_crystal_F_000 792 _exptl_crystal_size_max 0.323 _exptl_crystal_size_mid 0.1 _exptl_crystal_size_min 0.036 _refine_diff_density_max 0.862 _refine_diff_density_min -0.696 _refine_ls_extinction_coef 0.0100(5) _refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^ _refine_ls_extinction_method ; SHELXL97 (Sheldrick, 2008) ; _refine_ls_goodness_of_fit_ref 1.057 _refine_ls_matrix_type full _refine_ls_number_parameters 78 _refine_ls_number_reflns 931 _refine_ls_number_restraints 0 _refine_ls_restrained_S_all 1.057 _refine_ls_R_factor_all 0.0395 _refine_ls_R_factor_gt 0.0299 _refine_ls_shift/su_max 0 _refine_ls_shift/su_mean 0 _refine_ls_structure_factor_coef Fsqd _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0295P)^2^+3.6732P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_weighting_scheme calc _refine_ls_wR_factor_gt 0.0717 _refine_ls_wR_factor_ref 0.0761 _reflns_number_gt 773 _reflns_number_total 931 _reflns_threshold_expression >2\s(I) _iucr_refine_instructions_details ; TITL Pmmn 15 C face absortion correction CELL 0.71073 5.7363 13.8532 9.9330 90.000 90.000 90.000 ZERR 2 0.0006 0.0012 0.0010 0.000 0.000 0.000 LATT 1 SYMM 0.50000 - X , 0.50000 - Y , Z SYMM 0.50000 + X , - Y , - Z SYMM - X , 0.50000 + Y , - Z SFAC Ca O Rb Si UNIT 8 28 8 8 SHEL 999 0.80 L.S. 10 FMAP 2 PLAN 10 ACTA BOND EXYZ RB3 CA3 EADP RB3 CA3 REM M1, M2 = Rb; M3 = 50% Ca+ 50% Rb; M4, M5: Ca WGHT 0.029500 3.673200 EXTI 0.009997 FVAR 2.35803 RB1 3 0.750000 0.104859 0.085384 10.50000 0.01430 0.02612 = 0.01284 0.00023 0.00000 0.00000 RB2 3 0.250000 0.250000 0.258460 10.25000 0.01779 0.01374 = 0.01623 0.00000 0.00000 0.00000 RB3 3 0.250000 0.098017 0.586851 10.25000 0.01812 0.04126 = 0.01344 -0.00736 0.00000 0.00000 CA3 1 0.250000 0.098017 0.586851 10.25000 0.01812 0.04126 = 0.01344 -0.00736 0.00000 0.00000 CA4 1 0.750000 0.250000 0.749350 10.25000 0.01253 0.00688 = 0.01090 0.00000 0.00000 0.00000 CA5 1 0.250000 0.510582 0.248729 10.50000 0.01331 0.00734 = 0.00992 -0.00005 0.00000 0.00000 SI1 4 0.750000 0.136205 0.418685 10.50000 0.02244 0.01068 = 0.01163 -0.00010 0.00000 0.00000 SI2 4 0.250000 0.139629 0.919315 10.50000 0.00851 0.00747 = 0.01182 0.00237 0.00000 0.00000 O1 2 0.018112 0.127394 0.828042 11.00000 0.01710 0.02073 = 0.03200 0.00744 -0.01100 -0.00729 O2 2 0.250000 0.073375 1.051474 10.50000 0.01967 0.01782 = 0.01882 0.00742 0.00000 0.00000 O3 2 0.250000 0.250000 0.982027 10.25000 0.04339 0.01476 = 0.02053 0.00000 0.00000 0.00000 O4 2 0.524624 0.082246 0.360514 11.00000 0.05307 0.03234 = 0.04618 0.00469 -0.02495 -0.01842 O5 2 0.750000 0.250000 0.359918 10.25000 0.02102 0.01265 = 0.00920 0.00000 0.00000 0.00000 O6 2 0.750000 0.135548 0.578862 10.50000 0.07583 0.01682 = 0.01140 0.00021 0.00000 0.00000 HKLF 4 REM Pmmn REM R1 = 0.0299 for 773 Fo > 4sig(Fo) and 0.0395 for all 931 data REM 78 parameters refined using 0 restraints END WGHT 0.0295 3.6843 REM Highest difference peak 0.862, deepest hole -0.696, 1-sigma level 0.154 Q1 1 0.3175 0.0660 0.6379 11.00000 0.05 0.86 Q2 1 0.6379 0.1738 0.4647 11.00000 0.05 0.75 Q3 1 0.1507 0.2500 0.9387 10.50000 0.05 0.60 Q4 1 0.4989 0.0970 0.4406 11.00000 0.05 0.59 Q5 1 0.7500 0.1478 0.1778 10.50000 0.05 0.59 Q6 1 0.7500 0.0875 0.5853 10.50000 0.05 0.54 Q7 1 0.2500 0.0525 0.5343 10.50000 0.05 0.54 Q8 1 0.2500 -0.0386 1.0632 10.50000 0.05 0.53 Q9 1 0.7500 0.0630 0.0207 10.50000 0.05 0.53 Q10 1 0.2500 0.3178 0.2870 10.50000 0.05 0.52 ; _cod_data_source_file ef3065.cif _cod_data_source_block RT _cod_original_sg_symbol_H-M 'P m m n' _cod_database_code 2312757 loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, -y+1/2, z' 'x+1/2, -y, -z' '-x, y+1/2, -z' '-x, -y, -z' 'x-1/2, y-1/2, -z' '-x-1/2, y, z' 'x, -y-1/2, z' loop_ _atom_site_type_symbol _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_symmetry_multiplicity _atom_site_disorder_assembly _atom_site_disorder_group Rb Rb1 0.75 0.10486(5) 0.08538(6) 0.0178(2) Uani d S 1 2 . . Rb Rb2 0.25 0.25 0.25846(8) 0.0159(2) Uani d S 1 4 . . Rb Rb3 0.25 0.09802(7) 0.58685(8) 0.0243(3) Uani d SP 0.5 2 . . Ca Ca3 0.25 0.09802(7) 0.58685(8) 0.0243(3) Uani d SP 0.5 2 . . Ca Ca4 0.75 0.25 0.74935(15) 0.0101(4) Uani d S 1 4 . . Ca Ca5 0.25 0.51058(8) 0.24873(11) 0.0102(3) Uani d S 1 2 . . Si Si1 0.75 0.13621(12) 0.41868(17) 0.0149(4) Uani d S 1 2 . . Si Si2 0.25 0.13963(11) 0.91931(16) 0.0093(3) Uani d S 1 2 . . O O1 0.0181(5) 0.1274(2) 0.8280(3) 0.0233(8) Uani d . 1 1 . . O O2 0.25 0.0734(3) 1.0515(4) 0.0188(10) Uani d S 1 2 . . O O3 0.25 0.25 0.9820(7) 0.0262(15) Uani d S 1 4 . . O O4 0.5246(7) 0.0822(3) 0.3605(4) 0.0439(11) Uani d . 1 1 . . O O5 0.75 0.25 0.3599(6) 0.0143(12) Uani d S 1 4 . . O O6 0.75 0.1355(3) 0.5789(4) 0.0347(14) Uani d S 1 2 . . 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 Rb1 0.0143(3) 0.0261(4) 0.0128(3) 0 0 0.0002(2) Rb2 0.0178(5) 0.0137(4) 0.0162(4) 0 0 0 Rb3 0.0181(4) 0.0413(6) 0.0134(4) 0 0 -0.0074(4) Ca3 0.0181(4) 0.0413(6) 0.0134(4) 0 0 -0.0074(4) Ca4 0.0125(8) 0.0069(7) 0.0109(8) 0 0 0 Ca5 0.0133(6) 0.0073(5) 0.0099(6) 0 0 -0.0001(4) Si1 0.0224(9) 0.0107(8) 0.0116(8) 0 0 -0.0001(6) Si2 0.0085(7) 0.0075(7) 0.0118(8) 0 0 0.0024(6) O1 0.0171(16) 0.0207(16) 0.0320(19) -0.0073(13) -0.0110(14) 0.0074(13) O2 0.020(2) 0.018(2) 0.019(2) 0 0 0.0074(18) O3 0.043(4) 0.015(3) 0.021(3) 0 0 0 O4 0.053(3) 0.032(2) 0.046(2) -0.0184(19) -0.025(2) 0.0047(17) O5 0.021(3) 0.013(3) 0.009(3) 0 0 0 O6 0.076(4) 0.017(2) 0.011(2) 0 0 0.0002(18) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source Ca Ca 0.2262 0.3064 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.006 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' Rb Rb -0.9393 2.9676 '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' loop_ _exptl_crystal_face_index_h _exptl_crystal_face_index_k _exptl_crystal_face_index_l _exptl_crystal_face_perp_dist 2 -13 -10 0.095 -1 18 8 0.1266 5 -4 -4 0.0813 7 8 -1 0.0171 -7 -8 5 0.0316 -7 -7 -4 0.016 7 7 4 0.0165 -2 0 -14 0.0456 3 0 13 0.0338 -5 0 10 0.0524 loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle _geom_angle_publ_flag O2 Rb1 O2 5_656 1_554 79.25(8) ? O2 Rb1 O2 5_656 1_654 79.25(8) ? O2 Rb1 O2 1_554 1_654 158.25(17) ? O2 Rb1 O1 5_656 7_654 71.35(9) ? O2 Rb1 O1 1_554 7_654 54.11(10) ? O2 Rb1 O1 1_654 7_654 114.88(10) ? O2 Rb1 O1 5_656 1_654 71.35(9) ? O2 Rb1 O1 1_554 1_654 114.88(10) ? O2 Rb1 O1 1_654 1_654 54.11(10) ? O1 Rb1 O1 7_654 1_654 61.69(11) ? O2 Rb1 O4 5_656 7_755 110.08(10) ? O2 Rb1 O4 1_554 7_755 120.40(11) ? O2 Rb1 O4 1_654 7_755 70.77(11) ? O1 Rb1 O4 7_654 7_755 174.31(9) ? O1 Rb1 O4 1_654 7_755 123.98(9) ? O2 Rb1 O4 5_656 . 110.08(10) ? O2 Rb1 O4 1_554 . 70.77(11) ? O2 Rb1 O4 1_654 . 120.40(11) ? O1 Rb1 O4 7_654 . 123.98(9) ? O1 Rb1 O4 1_654 . 174.31(9) ? O4 Rb1 O4 7_755 . 50.35(14) ? O3 Rb2 O4 1_554 8_565 109.85(8) ? O3 Rb2 O4 1_554 2 109.85(8) ? O4 Rb2 O4 8_565 2 63.71(15) ? O3 Rb2 O4 1_554 7_655 109.85(8) ? O4 Rb2 O4 8_565 7_655 140.29(17) ? O4 Rb2 O4 2 7_655 102.26(13) ? O3 Rb2 O4 1_554 . 109.85(8) ? O4 Rb2 O4 8_565 . 102.26(13) ? O4 Rb2 O4 2 . 140.29(17) ? O4 Rb2 O4 7_655 . 63.71(15) ? O3 Rb2 O5 1_554 . 109.36(10) ? O4 Rb2 O5 8_565 . 52.37(7) ? O4 Rb2 O5 2 . 112.66(10) ? O4 Rb2 O5 7_655 . 112.66(10) ? O4 Rb2 O5 . . 52.37(7) ? O3 Rb2 O5 1_554 1_455 109.36(10) ? O4 Rb2 O5 8_565 1_455 112.66(10) ? O4 Rb2 O5 2 1_455 52.37(7) ? O4 Rb2 O5 7_655 1_455 52.37(7) ? O4 Rb2 O5 . 1_455 112.66(10) ? O5 Rb2 O5 . 1_455 141.3(2) ? O3 Rb2 O2 1_554 1_554 49.96(7) ? O4 Rb2 O2 8_565 1_554 144.54(9) ? O4 Rb2 O2 2 1_554 144.54(9) ? O4 Rb2 O2 7_655 1_554 67.82(10) ? O4 Rb2 O2 . 1_554 67.82(10) ? O5 Rb2 O2 . 1_554 102.31(6) ? O5 Rb2 O2 1_455 1_554 102.31(6) ? O3 Rb2 O2 1_554 2_554 49.96(7) ? O4 Rb2 O2 8_565 2_554 67.82(10) ? O4 Rb2 O2 2 2_554 67.82(10) ? O4 Rb2 O2 7_655 2_554 144.54(9) ? O4 Rb2 O2 . 2_554 144.54(9) ? O5 Rb2 O2 . 2_554 102.31(6) ? O5 Rb2 O2 1_455 2_554 102.31(6) ? O2 Rb2 O2 1_554 2_554 99.92(15) ? O4 Rb3 O4 7_655 . 69.79(16) ? O4 Rb3 O1 7_655 7_655 172.90(10) ? O4 Rb3 O1 . 7_655 116.29(9) ? O4 Rb3 O1 7_655 . 116.29(9) ? O4 Rb3 O1 . . 172.90(10) ? O1 Rb3 O1 7_655 . 57.39(12) ? O4 Rb3 O4 7_655 3_456 79.71(12) ? O4 Rb3 O4 . 3_456 109.79(8) ? O1 Rb3 O4 7_655 3_456 100.79(11) ? O1 Rb3 O4 . 3_456 75.71(10) ? O4 Rb3 O4 7_655 5_656 109.79(8) ? O4 Rb3 O4 . 5_656 79.71(12) ? O1 Rb3 O4 7_655 5_656 75.71(10) ? O1 Rb3 O4 . 5_656 100.79(11) ? O4 Rb3 O4 3_456 5_656 53.74(16) ? O4 Rb3 O6 7_655 . 123.68(12) ? O4 Rb3 O6 . . 55.20(12) ? O1 Rb3 O6 7_655 . 61.64(11) ? O1 Rb3 O6 . . 118.01(11) ? O4 Rb3 O6 3_456 . 127.25(12) ? O4 Rb3 O6 5_656 . 73.50(12) ? O4 Rb3 O6 7_655 1_455 55.20(12) ? O4 Rb3 O6 . 1_455 123.68(12) ? O1 Rb3 O6 7_655 1_455 118.01(11) ? O1 Rb3 O6 . 1_455 61.64(11) ? O4 Rb3 O6 3_456 1_455 73.50(12) ? O4 Rb3 O6 5_656 1_455 127.25(12) ? O6 Rb3 O6 . 1_455 159.22(18) ? O6 Ca4 O6 . 2_655 86.2(2) ? O6 Ca4 O1 . 8_665 135.66(10) ? O6 Ca4 O1 2_655 8_665 75.89(12) ? O6 Ca4 O1 . 2 135.66(10) ? O6 Ca4 O1 2_655 2 75.89(12) ? O1 Ca4 O1 8_665 2 78.88(14) ? O6 Ca4 O1 . 7_655 75.89(12) ? O6 Ca4 O1 2_655 7_655 135.66(10) ? O1 Ca4 O1 8_665 7_655 142.33(18) ? O1 Ca4 O1 2 7_655 89.11(14) ? O6 Ca4 O1 . 1_655 75.89(12) ? O6 Ca4 O1 2_655 1_655 135.66(10) ? O1 Ca4 O1 8_665 1_655 89.11(14) ? O1 Ca4 O1 2 1_655 142.33(18) ? O1 Ca4 O1 7_655 1_655 78.88(14) ? O2 Ca5 O4 2_554 2 97.40(13) ? O2 Ca5 O4 2_554 8_565 97.40(13) ? O4 Ca5 O4 2 8_565 85.7(2) ? O2 Ca5 O1 2_554 6_666 94.14(12) ? O4 Ca5 O1 2 6_666 168.20(13) ? O4 Ca5 O1 8_565 6_666 95.30(14) ? O2 Ca5 O1 2_554 4_556 94.14(12) ? O4 Ca5 O1 2 4_556 95.30(14) ? O4 Ca5 O1 8_565 4_556 168.20(13) ? O1 Ca5 O1 6_666 4_556 81.37(16) ? O2 Ca5 O6 2_554 6_566 165.38(16) ? O4 Ca5 O6 2 6_566 93.30(13) ? O4 Ca5 O6 8_565 6_566 93.30(13) ? O1 Ca5 O6 6_666 6_566 74.91(11) ? O1 Ca5 O6 4_556 6_566 74.91(11) ? O6 Si1 O4 . . 110.99(19) ? O6 Si1 O4 . 7_755 110.99(19) ? O4 Si1 O4 . 7_755 107.7(3) ? O6 Si1 O5 . . 110.6(3) ? O4 Si1 O5 . . 108.21(18) ? O4 Si1 O5 7_755 . 108.21(18) ? O2 Si2 O1 . . 113.52(14) ? O2 Si2 O1 . 7_655 113.52(14) ? O1 Si2 O1 . 7_655 110.5(3) ? O2 Si2 O3 . . 102.8(3) ? O1 Si2 O3 . . 107.96(17) ? O1 Si2 O3 7_655 . 107.96(17) ? Si2 O3 Si2 2 . 135.7(4) ? Si1 O5 Si1 2_655 . 139.4(4) ? loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag Rb1 O2 5_656 2.819(4) ? Rb1 O2 1_554 2.9206(9) ? Rb1 O2 1_654 2.9206(9) ? Rb1 O1 7_654 2.999(3) ? Rb1 O1 1_654 2.999(3) ? Rb1 O4 7_755 3.039(4) ? Rb1 O4 . 3.039(4) ? Rb1 O5 . 3.388(4) ? Rb2 O3 1_554 2.746(7) ? Rb2 O4 8_565 2.985(4) ? Rb2 O4 2 2.985(4) ? Rb2 O4 7_655 2.985(4) ? Rb2 O4 . 2.985(4) ? Rb2 O5 . 3.0401(19) ? Rb2 O5 1_455 3.0401(19) ? Rb2 O2 1_554 3.196(4) ? Rb2 O2 2_554 3.196(4) ? Rb3 O4 7_655 2.754(5) ? Rb3 O4 . 2.754(5) ? Rb3 O1 7_655 2.770(4) ? Rb3 O1 . 2.770(4) ? Rb3 O4 3_456 2.860(4) ? Rb3 O4 5_656 2.860(4) ? Rb3 O6 . 2.9160(9) ? Rb3 O6 1_455 2.9160(9) ? Ca4 O6 . 2.320(5) ? Ca4 O6 2_655 2.320(5) ? Ca4 O1 8_665 2.421(3) ? Ca4 O1 2 2.421(3) ? Ca4 O1 7_655 2.421(3) ? Ca4 O1 1_655 2.421(3) ? Ca5 O2 2_554 2.279(4) ? Ca5 O4 2 2.317(4) ? Ca5 O4 8_565 2.317(4) ? Ca5 O1 6_666 2.359(3) ? Ca5 O1 4_556 2.359(3) ? Ca5 O6 6_566 2.435(5) ? Si1 O6 . 1.591(5) ? Si1 O4 . 1.601(4) ? Si1 O4 7_755 1.601(4) ? Si1 O5 . 1.681(2) ? Si2 O2 . 1.602(4) ? Si2 O1 . 1.619(3) ? Si2 O1 7_655 1.619(3) ? Si2 O3 . 1.651(3) ? O1 Si2 . 1.619(3) ? O1 Ca5 6_556 2.359(3) ? O1 Ca4 1_455 2.421(3) ? O1 Rb3 . 2.770(4) ? O1 Rb1 1_456 2.999(3) ? O2 Si2 . 1.602(4) ? O2 Ca5 2_556 2.279(4) ? O2 Rb1 5_656 2.819(4) ? O2 Rb1 1_556 2.9206(9) ? O2 Rb1 1_456 2.9206(9) ? O2 Rb2 1_556 3.196(4) ? O3 Si2 2 1.651(3) ? O3 Si2 . 1.651(3) ? O3 Rb2 1_556 2.746(7) ? O4 Si1 . 1.601(4) ? O4 Ca5 2 2.317(4) ? O4 Rb3 . 2.754(5) ? O4 Rb3 5_656 2.860(4) ? O4 Rb2 . 2.985(4) ? O4 Rb1 . 3.039(4) ? O5 Si1 2_655 1.681(2) ? O5 Si1 . 1.681(2) ? O5 Rb2 1_655 3.0401(19) ? O5 Rb2 . 3.0401(19) ? O5 Rb1 2_655 3.388(4) ? O5 Rb1 . 3.388(4) ? O6 Si1 . 1.591(4) ? O6 Ca4 . 2.320(5) ? O6 Ca5 6_656 2.435(5) ? O6 Rb3 1_655 2.9160(9) ? O6 Rb3 . 2.9160(9) ?