#------------------------------------------------------------------------------ #$Date: 2008-01-13 22:15:36 +0000 (Sun, 13 Jan 2008) $ #$Revision: 14 $ #$URL: svn://www.crystallography.net/cod/cif/2/2003026.cif $ #------------------------------------------------------------------------------ # # This file is available in the Crystallography Open Database (COD), # http://www.crystallography.net/ # # All data on this site have been placed in the public domain by the # contributors. # data_2003026 _journal_name_full 'Acta Crystallographica, Section B' _journal_year 1998 _journal_volume B54 _journal_page_first 568 _journal_page_last 577 _chemical_name_systematic ; Potassium disilicate ; _chemical_formula_moiety 'K2 Si2 O5' _chemical_formula_sum 'K2 O5 Si2' _chemical_formula_weight 214.36 _symmetry_cell_setting Monoclinic _symmetry_space_group_name_H-M 'C c' _symmetry_space_group_name_Hall 'C -2yc' loop_ _symmetry_equiv_pos_as_xyz x,y,z x,-y,1/2+z 1/2+x,1/2+y,z 1/2+x,1/2-y,1/2+z _cell_length_a 16.3224(15) _cell_length_b 11.243(2) _cell_length_c 9.9190(10) _cell_angle_alpha 90 _cell_angle_beta 115.972(11) _cell_angle_gamma 90 _cell_volume 1636.4(4) _cell_formula_units_Z 12 _cell_measurement_reflns_used 25 _cell_measurement_theta_min 10 _cell_measurement_theta_max 14 _cell_measurement_temperature 150 _exptl_crystal_description 'irregular plate' _exptl_crystal_colour 'colorless' _exptl_crystal_size_max 0.25 _exptl_crystal_size_mid 0.25 _exptl_crystal_size_min 0.05 _exptl_crystal_density_diffrn 2.610 _exptl_crystal_density_meas 'Not measured' _exptl_crystal_F_000 1272 _exptl_absorpt_coefficient_mu 2.11 _exptl_absorpt_correction_type 'delabs (Spek, 1990)' _exptl_absorpt_correction_T_min 0.655 _exptl_absorpt_correction_T_max 1.000 _diffrn_ambient_temperature 150 _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_source 'Rotating Anode' _diffrn_radiation_monochromator 'graphite' _diffrn_measurement_device_type 'CAD4-T' _diffrn_measurement_method '\w-scan' _diffrn_reflns_number 3875 _diffrn_reflns_av_R_equivalents 0.0472 _diffrn_reflns_av_sigmaI/netI 0.0656 _diffrn_reflns_theta_min 2.28 _diffrn_reflns_theta_max 27.48 _diffrn_reflns_limit_h_min -12 _diffrn_reflns_limit_h_max 21 _diffrn_reflns_limit_k_min -14 _diffrn_reflns_limit_k_max 12 _diffrn_reflns_limit_l_min -12 _diffrn_reflns_limit_l_max 12 _diffrn_standards_number 1 _diffrn_standards_interval_time 60 _diffrn_standards_decay_% 0 _reflns_number_total 2711 _reflns_number_gt 2370 _reflns_threshold_expression I>2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.038 _refine_ls_R_factor_gt 0.038 _refine_ls_wR_factor_all 0.079 _refine_ls_wR_factor_ref 0.079 _refine_ls_restrained_S_all 1.031 _refine_ls_restrained_S_obs 1.048 _refine_ls_number_reflns 2711 _refine_ls_number_parameters 245 _refine_ls_hydrogen_treatment 'H-atom refinement: see text ' _refine_ls_weighting_scheme 'w = 1/[\s^2^(Fo^2^)+( 0.0304P)^2^] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_shift/su_max 0.000 _refine_ls_shift/esd_mean 0.000 _refine_diff_density_max 0.644 _refine_diff_density_min -0.671 _refine_ls_extinction_method none _refine_ls_abs_structure_details 'Flack H.D. (1983), Acta Cryst. A39, 876-881' loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source Si Si 0.0817 0.0704 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' O O 0.0106 0.0060 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' K K 0.2009 0.2494 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_thermal_displace_type _atom_site_occupancy Si1 0.50011(12) -0.01395(15) 0.3248(2) 0.0040(5) Uani 1.000 Si2 0.62183(12) 0.01784(15) 0.6661(2) 0.0038(5) Uani 1.000 Si3 0.22567(13) 0.2522(2) 0.3234(2) 0.0044(5) Uani 1.000 Si4 0.60753(13) 0.4814(2) 0.7217(2) 0.0044(4) Uani 1.000 Si5 0.47954(13) 0.4754(2) 0.3757(2) 0.0041(4) Uani 1.000 Si6 0.38525(12) 0.23002(15) 0.2370(2) 0.0041(5) Uani 1.000 O1 0.4583(3) 0.3328(4) 0.3390(5) 0.0074(12) Uani 1.000 O2 0.5162(3) 0.4843(4) 0.5595(5) 0.0056(12) Uani 1.000 O3 0.5893(3) 0.0176(4) 0.4837(5) 0.0090(12) Uani 1.000 O4 0.5357(3) 0.0589(3) 0.7007(5) 0.0046(7) Uani 1.000 O5 0.3991(3) 0.5592(4) 0.2873(5) 0.0120(12) Uani 1.000 O6 0.4395(3) -0.1160(4) 0.3395(5) 0.0081(12) Uani 1.000 O7 0.4481(3) 0.1115(4) 0.2631(5) 0.0091(12) Uani 1.000 O8 0.3217(3) 0.2031(4) 0.3238(5) 0.0091(12) Uani 1.000 O9 0.6452(3) 0.3443(4) 0.7316(5) 0.0106(12) Uani 1.000 O10 0.6793(3) 0.5816(4) 0.7464(5) 0.0076(12) Uani 1.000 O11 0.3272(3) 0.2569(4) 0.0671(5) 0.0084(14) Uani 1.000 O12 0.6625(3) -0.1035(4) 0.7433(5) 0.0080(12) Uani 1.000 O13 0.5691(3) 0.5087(4) 0.3501(5) 0.0113(14) Uani 1.000 O14 0.6954(3) 0.1282(4) 0.7173(5) 0.0068(12) Uani 1.000 O15 0.2431(3) 0.2742(4) 0.4891(5) 0.0094(14) Uani 1.000 K1 0.14223(11) 0.24318(12) 0.9315(2) 0.0077(4) Uani 1.000 K2 0.43965(10) 0.27459(13) 0.62413(15) 0.0083(4) Uani 1.000 K3 0.28439(12) 0.48510(14) 0.0186(2) 0.0183(5) Uani 1.000 K4 0.30054(11) 0.26042(13) 0.7824(2) 0.0068(4) Uani 1.000 K5 0.33909(10) 0.02082(13) 0.9686(2) 0.0093(4) Uani 1.000 K6 0.08806(11) 0.23334(13) 0.5199(2) 0.0099(4) Uani 1.000 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 Si1 0.0031(10) 0.0054(8) 0.0041(8) -0.0002(7) 0.0020(8) -0.0003(7) Si2 0.0040(10) 0.0049(8) 0.0028(8) -0.0007(7) 0.0017(7) -0.0003(7) Si3 0.0045(9) 0.0036(8) 0.0062(9) 0.0011(7) 0.0033(7) 0.0013(6) Si4 0.0037(8) 0.0047(7) 0.0058(8) 0.0006(7) 0.0030(7) -0.0001(7) Si5 0.0057(8) 0.0034(7) 0.0042(8) 0.0004(7) 0.0030(7) 0.0005(6) Si6 0.0033(9) 0.0037(7) 0.0053(8) 0.0005(7) 0.0019(7) -0.0014(6) O1 0.007(2) 0.007(2) 0.008(2) -0.002(2) 0.003(2) 0.000(2) O2 0.006(2) 0.006(2) 0.007(2) 0.003(2) 0.005(2) 0.004(2) O3 0.010(2) 0.014(2) 0.004(2) 0.001(2) 0.004(2) 0.000(2) O4 0.0046(12) 0.0060(12) 0.0045(12) 0.0004(9) 0.0031(9) 0.0018(9) O5 0.008(2) 0.012(2) 0.008(2) 0.005(2) -0.004(2) 0.000(2) O6 0.007(2) 0.010(2) 0.009(2) -0.005(2) 0.005(2) 0.000(2) O7 0.006(2) 0.007(2) 0.013(2) 0.002(2) 0.003(2) -0.004(2) O8 0.008(2) 0.010(2) 0.012(2) 0.000(2) 0.007(2) 0.001(2) O9 0.010(2) 0.011(2) 0.012(2) 0.001(2) 0.006(2) 0.000(2) O10 0.007(2) 0.004(2) 0.009(2) 0.000(2) 0.001(2) -0.001(2) O11 0.009(3) 0.010(2) 0.006(2) 0.002(2) 0.003(2) 0.000(2) O12 0.007(2) 0.010(2) 0.006(2) -0.003(2) 0.002(2) 0.001(2) O13 0.011(3) 0.018(2) 0.007(2) -0.006(2) 0.006(2) -0.004(2) O14 0.004(2) 0.009(2) 0.007(2) 0.000(2) 0.002(2) 0.003(2) O15 0.011(3) 0.013(2) 0.004(2) 0.003(2) 0.003(2) 0.000(2) K1 0.0070(7) 0.0092(7) 0.0087(7) -0.0016(6) 0.0050(5) -0.0014(5) K2 0.0084(8) 0.0082(6) 0.0085(7) -0.0004(6) 0.0039(6) 0.0010(5) K3 0.0214(10) 0.0070(7) 0.0120(7) -0.0010(6) -0.0061(7) 0.0007(6) K4 0.0057(7) 0.0081(6) 0.0081(6) 0.0005(6) 0.0044(5) 0.0010(5) K5 0.0091(7) 0.0085(6) 0.0091(6) 0.0001(6) 0.0028(6) -0.0019(5) K6 0.0120(8) 0.0073(6) 0.0080(6) 0.0006(6) 0.0021(6) 0.0002(5)