#------------------------------------------------------------------------------ #$Date: 2011-09-17 21:27:16 +0100 (Sat, 17 Sep 2011) $ #$Revision: 26029 $ #$URL: svn://www.crystallography.net/cod/cif/2/2103977.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_2103977 loop_ _publ_author_name 'Norberg, Stefan T.' 'Gustafsson, Joacim' 'Mellander, Bengt-Erik' _publ_section_title ; Phase transitions in KTP isostructures: correlation between structure and T~c~ in germanium-doped RbTiOPO~4~ ; _journal_issue 5 _journal_name_full 'Acta Crystallographica Section B' _journal_page_first 588 _journal_page_last 595 _journal_volume 59 _journal_year 2003 _chemical_formula_moiety 'Ge0.35 O10 P2 Rb2 Ti1.65' _chemical_formula_structural Rb2(Ge0.125Ti0.875)(Ge0.225Ti0.775)O2(PO4)2 _chemical_formula_sum 'Ge0.35 O10 P2 Rb2 Ti1.65' _chemical_formula_weight 497.28 _space_group_IT_number 33 _symmetry_cell_setting orthorhombic _symmetry_space_group_name_Hall 'P 2c -2n' _symmetry_space_group_name_H-M 'P n a 21' _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_formula_units_Z 4 _cell_length_a 12.9179(12) _cell_length_b 6.5189(8) _cell_length_c 10.3633(14) _cell_measurement_reflns_used 19 _cell_measurement_temperature 293(2) _cell_measurement_theta_max 29.58 _cell_measurement_theta_min 16.29 _cell_volume 872.70(18) _computing_cell_refinement ; CAD-4 Software (Enraf-Nonius, 1989) ; _computing_data_collection ; SMART (Siemens, 1995) ; _computing_data_reduction ; SAINT (Siemens, 1995) and SADABS (Sheldrick, 2001) ; _computing_molecular_graphics ; ORTEPIII for Windows (Farrugia, 1997) ; _computing_publication_material ; Xtal3.71 (Hall et al., 2000) programs: BONDLA; ATABLE; CIFIO ; _computing_structure_refinement ; Xtal3.71 (Hall et al., 2000) program: CRYLSQ ; _computing_structure_solution ; Atomic parameters from Norberg et al. (2000) ; _diffrn_ambient_temperature 293.0(10) _diffrn_measured_fraction_theta_full 0.997 _diffrn_measured_fraction_theta_max 0.997 _diffrn_measurement_device_type 'Siemens SMART CCD diffractometer' _diffrn_measurement_method \w _diffrn_radiation_monochromator graphite _diffrn_radiation_source 'normal-focus sealed tube' _diffrn_radiation_type 'Mo K\a' _diffrn_radiation_wavelength 0.71073 _diffrn_reflns_av_R_equivalents 0.039 _diffrn_reflns_av_sigmaI/netI 0.026 _diffrn_reflns_limit_h_max 18 _diffrn_reflns_limit_h_min -18 _diffrn_reflns_limit_k_max 9 _diffrn_reflns_limit_k_min -9 _diffrn_reflns_limit_l_max 14 _diffrn_reflns_limit_l_min -14 _diffrn_reflns_number 12604 _diffrn_reflns_theta_full 29.84 _diffrn_reflns_theta_max 29.84 _diffrn_reflns_theta_min 3.15 _diffrn_standards_decay_% none _exptl_absorpt_coefficient_mu 14.207 _exptl_absorpt_correction_T_max 0.564 _exptl_absorpt_correction_T_min 0.421 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_process_details '(SADABS; Sheldrick, 2001)' _exptl_crystal_colour Colourless _exptl_crystal_density_diffrn 3.785 _exptl_crystal_density_meas 'not measured' _exptl_crystal_description Rectangular _exptl_crystal_F_000 925.6 _exptl_crystal_size_max 0.095 _exptl_crystal_size_mid 0.05 _exptl_crystal_size_min 0.04 _refine_diff_density_max 0.73 _refine_diff_density_min -0.91 _refine_ls_abs_structure_details 'Flack (1983) parameter refined' _refine_ls_abs_structure_Flack 0.487(11) _refine_ls_extinction_expression no _refine_ls_extinction_method none _refine_ls_goodness_of_fit_all 1.044 _refine_ls_goodness_of_fit_ref 1.044 _refine_ls_hydrogen_treatment none _refine_ls_matrix_type full _refine_ls_number_constraints 34 _refine_ls_number_parameters 156 _refine_ls_number_reflns 2497 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.025 _refine_ls_R_factor_gt 0.025 _refine_ls_shift/su_max 0.00076 _refine_ls_shift/su_mean 0.00015 _refine_ls_structure_factor_coef F _refine_ls_weighting_details 'w = 1/[\s^2^(F) + 0.0020(F)^2^]' _refine_ls_weighting_scheme calc _refine_ls_wR_factor_all 0.039 _refine_ls_wR_factor_gt 0.039 _refine_ls_wR_factor_ref 0.039 _reflns_number_gt 2497 _reflns_number_total 2497 _reflns_threshold_expression F>0\s(F) _[local]_cod_data_source_file os0109.cif _[local]_cod_data_source_block GeRTP2 _[local]_cod_cif_authors_sg_H-M Pna21 _[local]_cod_cif_authors_sg_Hall 'p 2c -2n' _cod_depositor_comments ; The following automatic conversions were performed: '_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic' according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic' dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29. Automatic conversion script Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius ; _cod_database_code 2103977 loop_ _symmetry_equiv_pos_as_xyz +x,+y,+z -x,-y,1/2+z 1/2-x,1/2+y,1/2+z 1/2+x,1/2-y,+z loop_ _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_occupancy Rb1a 0.61351(7) 0.78509(13) 0.6842(3) 0.0204(6) Uani 0.883(8) Rb1b 0.6079(7) 0.7937(13) 0.6302(19) 0.0204(6) Uani 0.117(8) Rb2a 0.89346(7) 0.69529(14) 0.9373(3) 0.0183(6) Uani 0.939(6) Rb2b 0.8892(11) 0.705(2) 0.880(3) 0.0183(6) Uani 0.061(6) Ti1 0.62817(7) 0.49922(13) 1.0151(2) 0.0078(5) Uani 0.875(10) Ge1 0.62817(7) 0.49922(13) 1.0151(2) 0.0078(5) Uani 0.125(10) Ti2 0.75268(6) 0.25812(12) 0.7649(3) 0.0078(4) Uani 0.775(8) Ge2 0.75268(6) 0.25812(12) 0.7649(3) 0.0078(4) Uani 0.225(8) P1 0.50068(10) 0.3321(2) 0.7620(4) 0.0070(6) Uani 1 P2 0.82103(11) 0.5026(2) 0.5103(3) 0.0064(6) Uani 1 O1 0.5150(5) 0.4773(10) 0.8759(7) 0.015(3) Uani 1 O2 0.4860(5) 0.4610(10) 0.6390(7) 0.013(3) Uani 1 O3 0.5979(3) 0.1994(7) 0.7407(7) 0.011(2) Uani 1 O4 0.4050(3) 0.1940(7) 0.7845(5) 0.011(2) Uani 1 O11 0.7216(4) 0.4563(10) 0.8817(6) 0.011(2) Uani 1 O12 0.7765(5) 0.0514(9) 0.6353(6) 0.012(2) Uani 1 O5 0.8872(3) 0.3131(8) 0.4784(6) 0.013(2) Uani 1 O6 0.8875(4) 0.6919(9) 0.5404(7) 0.012(3) Uani 1 O7 0.7479(5) 0.5444(11) 0.3955(6) 0.014(2) Uani 1 O8 0.7487(5) 0.4587(10) 0.6258(6) 0.013(3) Uani 1 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 Rb1a 0.0195(4) 0.0107(3) 0.0310(12) -0.0042(2) 0.0076(4) -0.0028(4) Rb1b 0.0195(4) 0.0107(3) 0.0310(12) -0.0042(2) 0.0076(4) -0.0028(4) Rb2a 0.0120(3) 0.0157(4) 0.0271(9) -0.0043(2) 0.0016(4) -0.0023(4) Rb2b 0.0120(3) 0.0157(4) 0.0271(9) -0.0043(2) 0.0016(4) -0.0023(4) Ti1 0.0073(5) 0.0073(5) 0.0089(5) -0.0002(3) -0.0007(4) -0.0002(3) Ge1 0.0073(5) 0.0073(5) 0.0089(5) -0.0002(3) -0.0007(4) -0.0002(3) Ti2 0.0059(4) 0.0099(4) 0.0075(6) -0.0001(3) 0.0004(4) 0.0026(4) Ge2 0.0059(4) 0.0099(4) 0.0075(6) -0.0001(3) 0.0004(4) 0.0026(4) P1 0.0057(5) 0.0063(5) 0.0089(7) -0.0006(4) -0.0005(6) -0.0003(8) P2 0.0060(6) 0.0064(6) 0.0069(6) 0.0001(5) -0.0004(6) 0.0005(5) O1 0.010(3) 0.008(2) 0.025(3) 0.0028(19) -0.002(2) -0.006(2) O2 0.009(3) 0.015(3) 0.015(2) -0.003(2) -0.004(2) 0.006(2) O3 0.0059(17) 0.0100(19) 0.016(3) -0.0027(11) 0.001(2) -0.005(2) O4 0.007(2) 0.013(2) 0.012(3) -0.0011(13) 0.0012(15) 0.0007(16) O11 0.008(2) 0.014(2) 0.012(2) -0.004(2) 0.0017(18) -0.004(2) O12 0.013(3) 0.009(2) 0.014(2) 0.000(2) 0.002(2) -0.0022(18) O5 0.011(2) 0.008(2) 0.021(3) 0.0009(16) 0.0020(17) 0.0015(19) O6 0.016(3) 0.010(2) 0.011(3) -0.0013(18) -0.0041(19) 0.0001(19) O7 0.014(3) 0.016(2) 0.012(2) -0.004(2) -0.0050(19) 0.004(2) O8 0.015(3) 0.010(2) 0.015(2) 0.007(2) 0.006(2) 0.004(2) loop_ _atom_type_symbol _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source Rb -1.044 2.973 'Int. Tables Vol. IV Tables 2.2B and 2.3.1' Ge 0.081 1.801 'Int. Tables Vol. IV Tables 2.2B and 2.3.1' Ti 0.248 0.446 'Int. Tables Vol. IV Tables 2.2B and 2.3.1' P 0.09 0.095 'Int. Tables Vol. IV Tables 2.2B and 2.3.1' O 0.008 0.006 'Int. Tables Vol. IV Tables 2.2B and 2.3.1' 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 O1 Rb1a O2 . . 50.1(2) no O1 Rb1a O11 . . 49.49(16) no O1 Rb1a O8 . . 84.44(18) no O1 Rb1a O3 . '1 565' 117.8(2) no O1 Rb1a O12 . '1 565' 146.5(2) no O1 Rb1a O5 . '3 655' 52.92(17) no O1 Rb1a O7 . '3 655' 97.4(2) no O1 Rb1a O6 . '4 465' 87.45(16) no O2 Rb1a O11 . . 81.80(18) no O2 Rb1a O8 . . 75.63(19) no O2 Rb1a O3 . '1 565' 138.54(16) no O2 Rb1a O12 . '1 565' 156.1(2) no O2 Rb1a O5 . '3 655' 102.49(19) no O2 Rb1a O7 . '3 655' 147.3(2) no O2 Rb1a O6 . '4 465' 54.44(17) no O11 Rb1a O8 . . 51.40(17) no O11 Rb1a O3 . '1 565' 122.4(2) no O11 Rb1a O12 . '1 565' 101.52(17) no O11 Rb1a O5 . '3 655' 54.30(15) no O11 Rb1a O7 . '3 655' 71.87(17) no O11 Rb1a O6 . '4 465' 133.85(15) no O8 Rb1a O3 . '1 565' 145.73(16) no O8 Rb1a O12 . '1 565' 87.88(18) no O8 Rb1a O5 . '3 655' 105.13(17) no O8 Rb1a O7 . '3 655' 101.14(18) no O8 Rb1a O6 . '4 465' 119.23(19) no O3 Rb1a O12 '1 565' '1 565' 58.95(15) no O3 Rb1a O5 '1 565' '3 655' 74.4(2) no O3 Rb1a O7 '1 565' '3 655' 53.05(17) no O3 Rb1a O6 '1 565' '4 465' 89.24(15) no O12 Rb1a O5 '1 565' '3 655' 98.44(17) no O12 Rb1a O7 '1 565' '3 655' 52.27(17) no O12 Rb1a O6 '1 565' '4 465' 124.31(19) no O5 Rb1a O7 '3 655' '3 655' 46.18(15) no O5 Rb1a O6 '3 655' '4 465' 116.62(16) no O7 Rb1a O6 '3 655' '4 465' 139.62(16) no O2 Rb1b O8 . . 75.8(3) no O2 Rb1b O3 . '1 565' 134.5(5) no O2 Rb1b O12 . '1 565' 163.4(4) no O2 Rb1b O6 . '4 465' 58.5(3) no O8 Rb1b O3 . '1 565' 137.7(5) no O8 Rb1b O12 . '1 565' 87.9(3) no O8 Rb1b O6 . '4 465' 128.8(4) no O3 Rb1b O12 '1 565' '1 565' 57.9(2) no O3 Rb1b O6 '1 565' '4 465' 93.0(3) no O12 Rb1b O6 '1 565' '4 465' 137.6(4) no O11 Rb2a O5 . '2 765' 144.28(17) no O11 Rb2a O2 . '3 655' 148.0(2) no O11 Rb2a O3 . '3 655' 103.93(16) no O11 Rb2a O12 . '3 655' 53.81(17) no O11 Rb2a O7 . '3 655' 84.69(18) no O11 Rb2a O8 . '3 655' 88.20(18) no O11 Rb2a O4 . 4 56.91(16) no O11 Rb2a O1 . '4 565' 148.5(2) no O5 Rb2a O2 '2 765' '3 655' 54.50(17) no O5 Rb2a O3 '2 765' '3 655' 79.42(16) no O5 Rb2a O12 '2 765' '3 655' 125.9(2) no O5 Rb2a O7 '2 765' '3 655' 130.43(16) no O5 Rb2a O8 '2 765' '3 655' 119.29(18) no O5 Rb2a O4 '2 765' 4 90.76(14) no O5 Rb2a O1 '2 765' '4 565' 58.66(17) no O2 Rb2a O3 '3 655' '3 655' 46.37(15) no O2 Rb2a O12 '3 655' '3 655' 94.38(18) no O2 Rb2a O7 '3 655' '3 655' 88.81(18) no O2 Rb2a O8 '3 655' '3 655' 65.08(17) no O2 Rb2a O4 '3 655' 4 142.86(15) no O2 Rb2a O1 '3 655' '4 565' 55.7(2) no O3 Rb2a O12 '3 655' '3 655' 51.38(14) no O3 Rb2a O7 '3 655' '3 655' 99.33(16) no O3 Rb2a O8 '3 655' '3 655' 53.32(14) no O3 Rb2a O4 '3 655' 4 122.26(14) no O3 Rb2a O1 '3 655' '4 565' 101.89(18) no O12 Rb2a O7 '3 655' '3 655' 83.91(17) no O12 Rb2a O8 '3 655' '3 655' 50.09(16) no O12 Rb2a O4 '3 655' 4 97.30(14) no O12 Rb2a O1 '3 655' '4 565' 141.9(2) no O7 Rb2a O8 '3 655' '3 655' 46.92(17) no O7 Rb2a O4 '3 655' 4 127.38(18) no O7 Rb2a O1 '3 655' '4 565' 73.62(18) no O8 Rb2a O4 '3 655' 4 144.11(15) no O8 Rb2a O1 '3 655' '4 565' 93.05(18) no O4 Rb2a O1 4 '4 565' 120.8(2) no O11 Rb2b O5 . '2 765' 136.7(8) no O11 Rb2b O7 . '3 655' 88.1(4) no O11 Rb2b O4 . 4 60.1(4) no O11 Rb2b O1 . '4 565' 165.0(6) no O5 Rb2b O7 '2 765' '3 655' 126.8(7) no O5 Rb2b O4 '2 765' 4 90.7(4) no O5 Rb2b O1 '2 765' '4 565' 56.9(3) no O7 Rb2b O4 '3 655' 4 142.4(8) no O7 Rb2b O1 '3 655' '4 565' 76.9(4) no O4 Rb2b O1 4 '4 565' 133.0(8) no O1 Ti1 O11 . . 86.0(3) no O1 Ti1 O2 . '2 665' 86.2(3) no O1 Ti1 O6 . '3 645' 87.2(3) no O1 Ti1 O12 . '3 655' 173.0(3) no O1 Ti1 O5 . '3 655' 82.7(2) no O11 Ti1 O2 . '2 665' 172.2(3) no O11 Ti1 O6 . '3 645' 90.7(3) no O11 Ti1 O12 . '3 655' 95.8(3) no O11 Ti1 O5 . '3 655' 94.2(3) no O2 Ti1 O6 '2 665' '3 645' 88.3(3) no O2 Ti1 O12 '2 665' '3 655' 92.0(3) no O2 Ti1 O5 '2 665' '3 655' 85.3(2) no O6 Ti1 O12 '3 645' '3 655' 99.6(3) no O6 Ti1 O5 '3 645' '3 655' 168.4(2) no O12 Ti1 O5 '3 655' '3 655' 90.3(3) no O1 Ge1 O11 . . 86.0(3) no O1 Ge1 O2 . '2 665' 86.2(3) no O1 Ge1 O6 . '3 645' 87.2(3) no O1 Ge1 O12 . '3 655' 173.0(3) no O1 Ge1 O5 . '3 655' 82.7(2) no O11 Ge1 O2 . '2 665' 172.2(3) no O11 Ge1 O6 . '3 645' 90.7(3) no O11 Ge1 O12 . '3 655' 95.8(3) no O11 Ge1 O5 . '3 655' 94.2(3) no O2 Ge1 O6 '2 665' '3 645' 88.3(3) no O2 Ge1 O12 '2 665' '3 655' 92.0(3) no O2 Ge1 O5 '2 665' '3 655' 85.3(2) no O6 Ge1 O12 '3 645' '3 655' 99.6(3) no O6 Ge1 O5 '3 645' '3 655' 168.4(2) no O12 Ge1 O5 '3 655' '3 655' 90.3(3) no O3 Ti2 O11 . . 89.9(3) no O3 Ti2 O12 . . 86.6(3) no O3 Ti2 O8 . . 90.5(3) no O3 Ti2 O7 . '3 645' 87.0(3) no O3 Ti2 O4 . 4 177.8(2) no O11 Ti2 O12 . . 176.0(3) no O11 Ti2 O8 . . 90.6(3) no O11 Ti2 O7 . '3 645' 92.6(3) no O11 Ti2 O4 . 4 92.2(2) no O12 Ti2 O8 . . 87.6(3) no O12 Ti2 O7 . '3 645' 89.1(3) no O12 Ti2 O4 . 4 91.3(2) no O8 Ti2 O7 . '3 645' 176.0(3) no O8 Ti2 O4 . 4 89.8(2) no O7 Ti2 O4 '3 645' 4 92.6(2) no O3 Ge2 O11 . . 89.9(3) no O3 Ge2 O12 . . 86.6(3) no O3 Ge2 O8 . . 90.5(3) no O3 Ge2 O7 . '3 645' 87.0(3) no O3 Ge2 O4 . 4 177.8(2) no O11 Ge2 O12 . . 176.0(3) no O11 Ge2 O8 . . 90.6(3) no O11 Ge2 O7 . '3 645' 92.6(3) no O11 Ge2 O4 . 4 92.2(2) no O12 Ge2 O8 . . 87.6(3) no O12 Ge2 O7 . '3 645' 89.1(3) no O12 Ge2 O4 . 4 91.3(2) no O8 Ge2 O7 . '3 645' 176.0(3) no O8 Ge2 O4 . 4 89.8(2) no O7 Ge2 O4 '3 645' 4 92.6(2) no O1 P1 O2 . . 108.5(4) no O1 P1 O3 . . 111.1(4) no O1 P1 O4 . . 110.0(4) no O2 P1 O3 . . 106.8(4) no O2 P1 O4 . . 110.1(3) no O3 P1 O4 . . 110.3(2) no O5 P2 O6 . . 112.2(3) no O5 P2 O7 . . 108.4(4) no O5 P2 O8 . . 110.7(3) no O6 P2 O7 . . 110.9(4) no O6 P2 O8 . . 109.3(4) no O7 P2 O8 . . 105.1(3) no 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 Rb1a O1 . 3.098(7) no Rb1a O2 . 2.720(7) no Rb1a O3 '1 565' 2.771(5) no Rb1a O11 . 3.277(7) no Rb1a O12 '1 565' 2.776(6) no Rb1a O5 '3 655' 3.055(7) no Rb1a O6 '4 465' 3.281(6) no Rb1a O7 '3 655' 3.295(7) no Rb1a O8 . 2.818(6) no Rb1a Rb1b . 0.57(2) no Rb1b O2 . 2.682(11) no Rb1b O3 '1 565' 2.886(12) no Rb1b O12 '1 565' 2.751(10) no Rb1b O6 '4 465' 2.996(12) no Rb1b O8 . 2.842(11) no Rb2a O1 '4 565' 2.725(6) no Rb2a O2 '3 655' 3.130(7) no Rb2a O3 '3 655' 3.147(8) no Rb2a O4 4 2.995(5) no Rb2a O11 . 2.773(6) no Rb2a O12 '3 655' 3.149(6) no Rb2a O5 '2 765' 2.866(5) no Rb2a O7 '3 655' 2.950(7) no Rb2a O8 '3 655' 3.184(7) no Rb2a Rb2b . 0.60(3) no Rb2b O1 '4 565' 2.632(16) no Rb2b O4 4 2.792(19) no Rb2b O11 . 2.706(16) no Rb2b O5 '2 765' 3.067(18) no Rb2b O7 '3 655' 2.837(16) no Ti1 O1 . 2.058(7) no Ti1 O2 '2 665' 1.973(7) no Ti1 O11 . 1.856(6) no Ti1 O12 '3 655' 1.785(6) no Ti1 O5 '3 655' 2.090(5) no Ti1 O6 '3 645' 2.030(6) no Ge1 O1 . 2.058(7) no Ge1 O2 '2 665' 1.973(7) no Ge1 O11 . 1.856(6) no Ge1 O12 '3 655' 1.785(6) no Ge1 O5 '3 655' 2.090(5) no Ge1 O6 '3 645' 2.030(6) no Ti2 O3 . 2.051(4) no Ti2 O4 4 2.003(4) no Ti2 O11 . 1.816(7) no Ti2 O12 . 1.927(7) no Ti2 O7 '3 645' 1.942(7) no Ti2 O8 . 1.947(7) no Ge2 O3 . 2.051(4) no Ge2 O4 4 2.003(4) no Ge2 O11 . 1.816(7) no Ge2 O12 . 1.927(7) no Ge2 O7 '3 645' 1.942(7) no Ge2 O8 . 1.947(7) no P1 O1 . 1.525(8) no P1 O2 . 1.538(8) no P1 O3 . 1.540(4) no P1 O4 . 1.546(5) no P2 O5 . 1.538(5) no P2 O6 . 1.536(6) no P2 O7 . 1.544(7) no P2 O8 . 1.545(7) no