#------------------------------------------------------------------------------ #$Date: 2015-02-25 13:01:53 +0000 (Wed, 25 Feb 2015) $ #$Revision: 132410 $ #$URL: svn://www.crystallography.net/cod/cif/2/10/49/2104987.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_2104987 loop_ _publ_author_name 'Liu, Xiaogang' 'Cole, Jacqueline M.' 'Waddell, Paul G.' 'Lin, Tze-Chia' _publ_section_title ; Molecular origins of commercial laser dye functionality in azacoumarins and 2-quinolones: LD 425, LD 489 and LD 473 ; _journal_issue 6 _journal_name_full 'Acta Crystallographica Section B' _journal_page_first 560 _journal_page_last 568 _journal_volume 67 _journal_year 2011 _chemical_formula_moiety 'C15 H15 F3 N2 O2' _chemical_formula_sum 'C15 H15 F3 N2 O2' _chemical_formula_weight 312.29 _chemical_name_common 'LD 489' _chemical_name_systematic ? _space_group_IT_number 14 _symmetry_cell_setting monoclinic _symmetry_space_group_name_Hall '-P 2ybc' _symmetry_space_group_name_H-M 'P 1 21/c 1' _atom_sites_solution_hydrogens geom _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _audit_creation_method SHELXL-97 _cell_angle_alpha 90.00 _cell_angle_beta 102.537(3) _cell_angle_gamma 90.00 _cell_formula_units_Z 4 _cell_length_a 8.9941(5) _cell_length_b 11.2954(6) _cell_length_c 14.3536(9) _cell_measurement_reflns_used 11391 _cell_measurement_temperature 180(2) _cell_measurement_theta_max 27.485 _cell_measurement_theta_min 0.998 _cell_volume 1423.44(14) _computing_cell_refinement ; ; _computing_data_collection 'COLLECT (Nonius BV, 1998)' _computing_data_reduction ; ; _computing_molecular_graphics 'ORTEP-3 for Windows (Farrugia, 1997)' _computing_publication_material 'publCIF (Westrip, 2010)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _diffrn_ambient_temperature 180(2) _diffrn_detector_area_resol_mean 9 _diffrn_measured_fraction_theta_full 0.986 _diffrn_measured_fraction_theta_max 0.986 _diffrn_measurement_device_type KappaCCD _diffrn_measurement_method CCD _diffrn_radiation_monochromator graphite _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_reflns_av_R_equivalents 0.0324 _diffrn_reflns_av_sigmaI/netI 0.0475 _diffrn_reflns_limit_h_max 11 _diffrn_reflns_limit_h_min -11 _diffrn_reflns_limit_k_max 14 _diffrn_reflns_limit_k_min -12 _diffrn_reflns_limit_l_max 18 _diffrn_reflns_limit_l_min -18 _diffrn_reflns_number 7357 _diffrn_reflns_theta_full 27.39 _diffrn_reflns_theta_max 27.39 _diffrn_reflns_theta_min 3.76 _exptl_absorpt_coefficient_mu 0.124 _exptl_absorpt_correction_T_max 0.998 _exptl_absorpt_correction_T_min 0.958 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_process_details '(Blessing, 1997)' _exptl_crystal_colour Orange _exptl_crystal_density_diffrn 1.457 _exptl_crystal_density_method 'not measured' _exptl_crystal_description Unknown _exptl_crystal_F_000 648 _exptl_crystal_size_max 0.42 _exptl_crystal_size_mid 0.22 _exptl_crystal_size_min 0.14 _refine_diff_density_max 0.311 _refine_diff_density_min -0.252 _refine_ls_extinction_method none _refine_ls_goodness_of_fit_ref 1.039 _refine_ls_hydrogen_treatment refall _refine_ls_matrix_type full _refine_ls_number_parameters 259 _refine_ls_number_reflns 3199 _refine_ls_number_restraints 0 _refine_ls_restrained_S_all 1.039 _refine_ls_R_factor_all 0.0758 _refine_ls_R_factor_gt 0.0476 _refine_ls_shift/su_max 0.002 _refine_ls_shift/su_mean 0.001 _refine_ls_structure_factor_coef Fsqd _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0596P)^2^+0.3202P] where P=(Fo^2^+2Fc^2^)/3' _refine_ls_weighting_scheme calc _refine_ls_wR_factor_gt 0.1131 _refine_ls_wR_factor_ref 0.1271 _reflns_number_gt 2235 _reflns_number_total 3199 _reflns_threshold_expression >2sigma(I) _iucr_refine_instructions_details ; TITL jc0204 in P2(1)/c CELL 0.71073 8.9941 11.2954 14.3536 90.000 102.537 90.000 ZERR 4.00 0.0005 0.0006 0.0009 0.000 0.003 0.000 LATT 1 SYMM -X, 0.5+Y, 0.5-Z SFAC C H O N F UNIT 60 60 8 8 12 OMIT 0 1 1 OMIT 1 0 0 OMIT 1 1 0 OMIT 0 0 2 OMIT 0 2 0 OMIT -1 1 1 OMIT -1 0 2 OMIT 1 1 1 OMIT 0 1 2 L.S. 2 ACTA BOND $H FMAP 2 PLAN 5 CONF WGHT 0.059600 0.320200 FVAR 0.251510 TEMP -93 MOLE 1 C1 1 0.247701 0.789479 0.149852 11.000000 0.044830 0.032320 = 0.043240 -0.001500 0.016270 0.005910 C2 1 0.808182 0.465231 0.073621 11.000000 0.026360 0.035160 = 0.036360 -0.001290 0.007720 0.000730 C3 1 0.789766 0.559643 0.005175 11.000000 0.028020 0.039210 = 0.033920 -0.000090 0.011200 -0.001750 C4 1 0.679159 0.641963 0.001193 11.000000 0.029170 0.029820 = 0.028310 -0.001640 0.006690 -0.004600 C5 1 0.457574 0.716815 0.070803 11.000000 0.034570 0.024200 = 0.032010 0.001760 0.008840 -0.001120 C6 1 0.368216 0.701969 0.135690 11.000000 0.032730 0.026000 = 0.034470 -0.003050 0.010830 -0.000720 C7 1 0.395725 0.599134 0.195456 11.000000 0.032040 0.029910 = 0.027350 -0.003580 0.009130 -0.004130 C8 1 0.594124 0.544200 0.130096 11.000000 0.026080 0.028310 = 0.028130 -0.003230 0.004760 -0.001750 C9 1 0.576258 0.636786 0.064695 11.000000 0.028380 0.026050 = 0.026220 -0.000380 0.005560 -0.001810 C10 1 0.122366 0.721984 0.182029 11.000000 0.033310 0.044080 = 0.044940 -0.002000 0.014800 0.005730 C11 1 0.179469 0.648279 0.271116 11.000000 0.038390 0.042310 = 0.040140 -0.005750 0.016690 -0.000990 C12 1 0.357133 0.480456 0.329470 11.000000 0.064840 0.051400 = 0.053860 0.019950 0.031370 0.009950 C13 1 0.668244 0.741568 -0.069260 11.000000 0.040560 0.036990 = 0.040040 0.003650 0.017690 0.000740 C14 1 0.186397 0.865478 0.062771 11.000000 0.054880 0.043610 = 0.055120 0.010650 0.024500 0.018990 C15 1 0.051393 0.575484 0.295477 11.000000 0.043930 0.063820 = 0.052400 0.002650 0.021470 -0.006520 F1 5 0.762676 0.729827 -0.127936 11.000000 0.063670 0.065770 = 0.062270 0.025710 0.041860 0.015250 F2 5 0.701220 0.845482 -0.023971 11.000000 0.095940 0.034140 = 0.065270 0.002140 0.027470 -0.016430 F3 5 0.528727 0.752676 -0.123636 11.000000 0.050760 0.054770 = 0.046320 0.019360 0.011160 0.012570 H1 2 0.297851 0.844306 0.207205 11.000000 0.057150 H3 2 0.862643 0.563302 -0.034174 11.000000 0.034750 H5 2 0.440258 0.781186 0.028778 11.000000 0.033810 H11 2 0.219428 0.704826 0.327071 11.000000 0.053440 H10A 2 0.042599 0.773965 0.192704 11.000000 0.044630 H12A 2 0.345937 0.508762 0.394604 11.000000 0.088050 H14A 2 0.102320 0.917481 0.072711 11.000000 0.067320 H15A 2 -0.035708 0.627904 0.294039 11.000000 0.070100 H10B 2 0.071328 0.663156 0.128822 11.000000 0.050930 H12B 2 0.458502 0.456098 0.328190 11.000000 0.116950 H14B 2 0.263538 0.918226 0.047769 11.000000 0.060150 H15B 2 0.080386 0.536967 0.359804 11.000000 0.066390 H12C 2 0.292083 0.418630 0.314936 11.000000 0.092280 H14C 2 0.139158 0.808380 0.008560 11.000000 0.090140 H15C 2 0.020929 0.507293 0.243015 11.000000 0.072090 N1 4 0.509780 0.523445 0.192482 11.000000 0.031890 0.029570 = 0.031310 0.001980 0.010020 0.000580 N2 4 0.307194 0.572857 0.258043 11.000000 0.039470 0.034560 = 0.037510 0.003130 0.018040 0.001910 O1 3 0.707631 0.461322 0.133958 11.000000 0.030230 0.033520 = 0.036910 0.006630 0.011000 0.006140 O2 3 0.905599 0.388808 0.085032 11.000000 0.036130 0.043700 = 0.054270 0.006600 0.014910 0.010320 HKLF 4 END ; _[local]_cod_data_source_file bk5105.cif _[local]_cod_data_source_block ld489 _[local]_cod_cif_authors_sg_H-M P_21/c _cod_database_code 2104987 loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z+1/2' '-x, -y, -z' 'x, -y-1/2, z-1/2' 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_occupancy _atom_site_symmetry_multiplicity C C1 0.2477(2) 0.78948(17) 0.14985(14) 0.0391(4) Uani d 1 1 C C2 0.80818(19) 0.46523(15) 0.07362(12) 0.0325(4) Uani d 1 1 C C3 0.7898(2) 0.55964(16) 0.00517(13) 0.0330(4) Uani d 1 1 C C4 0.67916(19) 0.64196(14) 0.00119(12) 0.0290(4) Uani d 1 1 C C5 0.45757(19) 0.71682(15) 0.07080(12) 0.0300(4) Uani d 1 1 C C6 0.36822(19) 0.70197(14) 0.13569(12) 0.0305(4) Uani d 1 1 C C7 0.39573(19) 0.59913(14) 0.19546(12) 0.0294(4) Uani d 1 1 C C8 0.59412(18) 0.54420(14) 0.13010(11) 0.0277(4) Uani d 1 1 C C9 0.57626(18) 0.63679(14) 0.06469(11) 0.0269(4) Uani d 1 1 C C10 0.1224(2) 0.72198(18) 0.18203(15) 0.0398(5) Uani d 1 1 C C11 0.1795(2) 0.64828(17) 0.27112(14) 0.0390(4) Uani d 1 1 C C12 0.3571(3) 0.4805(2) 0.32947(19) 0.0539(6) Uani d 1 1 C C13 0.6682(2) 0.74157(16) -0.06926(13) 0.0378(4) Uani d 1 1 C C14 0.1864(3) 0.8655(2) 0.06277(17) 0.0493(6) Uani d 1 1 C C15 0.0514(3) 0.5755(2) 0.29548(18) 0.0517(6) Uani d 1 1 F F1 0.76268(15) 0.72983(11) -0.12794(9) 0.0596(4) Uani d 1 1 F F2 0.70122(17) 0.84548(10) -0.02397(10) 0.0636(4) Uani d 1 1 F F3 0.52873(13) 0.75268(10) -0.12364(8) 0.0505(3) Uani d 1 1 H H1 0.298(3) 0.844(2) 0.2072(17) 0.057(6) Uiso d 1 1 H H3 0.863(2) 0.5633(16) -0.0342(13) 0.035(5) Uiso d 1 1 H H5 0.440(2) 0.7812(17) 0.0288(14) 0.034(5) Uiso d 1 1 H H11 0.219(2) 0.705(2) 0.3271(16) 0.053(6) Uiso d 1 1 H H10A 0.043(2) 0.7740(18) 0.1927(14) 0.045(5) Uiso d 1 1 H H12A 0.346(3) 0.509(3) 0.395(2) 0.088(9) Uiso d 1 1 H H14A 0.102(3) 0.917(2) 0.0727(18) 0.067(7) Uiso d 1 1 H H15A -0.036(3) 0.628(2) 0.2940(18) 0.070(8) Uiso d 1 1 H H10B 0.071(2) 0.6632(19) 0.1288(16) 0.051(6) Uiso d 1 1 H H12B 0.459(4) 0.456(3) 0.328(3) 0.117(12) Uiso d 1 1 H H14B 0.264(3) 0.918(2) 0.0478(16) 0.060(7) Uiso d 1 1 H H15B 0.080(3) 0.537(2) 0.3598(19) 0.066(7) Uiso d 1 1 H H12C 0.292(4) 0.419(3) 0.315(2) 0.092(10) Uiso d 1 1 H H14C 0.139(3) 0.808(3) 0.009(2) 0.090(9) Uiso d 1 1 H H15C 0.021(3) 0.507(2) 0.2430(18) 0.072(7) Uiso d 1 1 N N1 0.50978(16) 0.52345(12) 0.19248(10) 0.0304(3) Uani d 1 1 N N2 0.30719(17) 0.57286(13) 0.25804(11) 0.0357(4) Uani d 1 1 O O1 0.70763(13) 0.46132(10) 0.13396(8) 0.0330(3) Uani d 1 1 O O2 0.90560(14) 0.38881(12) 0.08503(10) 0.0439(4) Uani d 1 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 C1 0.0448(11) 0.0323(9) 0.0432(11) 0.0059(8) 0.0163(9) -0.0015(9) C2 0.0264(8) 0.0352(9) 0.0364(9) 0.0007(7) 0.0077(7) -0.0013(8) C3 0.0280(9) 0.0392(10) 0.0339(9) -0.0017(7) 0.0112(7) -0.0001(8) C4 0.0292(8) 0.0298(9) 0.0283(8) -0.0046(7) 0.0067(7) -0.0016(7) C5 0.0346(9) 0.0242(8) 0.0320(9) -0.0011(7) 0.0088(7) 0.0018(7) C6 0.0327(9) 0.0260(8) 0.0345(9) -0.0007(7) 0.0108(7) -0.0031(7) C7 0.0320(9) 0.0299(9) 0.0273(8) -0.0041(7) 0.0091(7) -0.0036(7) C8 0.0261(8) 0.0283(8) 0.0281(8) -0.0017(7) 0.0048(7) -0.0032(7) C9 0.0284(8) 0.0261(8) 0.0262(8) -0.0018(7) 0.0056(7) -0.0004(7) C10 0.0333(10) 0.0441(11) 0.0449(11) 0.0057(9) 0.0148(8) -0.0020(10) C11 0.0384(10) 0.0423(11) 0.0401(10) -0.0010(8) 0.0167(8) -0.0058(9) C12 0.0648(16) 0.0514(14) 0.0539(14) 0.0100(12) 0.0314(12) 0.0199(12) C13 0.0406(10) 0.0370(10) 0.0400(10) 0.0007(8) 0.0177(8) 0.0036(8) C14 0.0549(14) 0.0436(12) 0.0551(13) 0.0190(11) 0.0245(11) 0.0107(11) C15 0.0439(12) 0.0638(14) 0.0524(13) -0.0065(11) 0.0215(10) 0.0027(12) F1 0.0637(8) 0.0658(8) 0.0623(8) 0.0152(6) 0.0419(7) 0.0257(7) F2 0.0959(11) 0.0341(6) 0.0653(8) -0.0164(6) 0.0275(8) 0.0021(6) F3 0.0508(7) 0.0548(7) 0.0463(6) 0.0126(5) 0.0112(5) 0.0194(6) N1 0.0319(8) 0.0296(7) 0.0313(7) 0.0006(6) 0.0100(6) 0.0020(6) N2 0.0395(8) 0.0346(8) 0.0375(8) 0.0019(6) 0.0180(7) 0.0031(7) O1 0.0302(6) 0.0335(7) 0.0369(6) 0.0061(5) 0.0110(5) 0.0066(5) O2 0.0361(7) 0.0437(8) 0.0543(8) 0.0103(6) 0.0149(6) 0.0066(7) loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source C C 0.0033 0.0016 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' H H 0.0000 0.0000 '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' N N 0.0061 0.0033 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' F F 0.0171 0.0103 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle C6 C1 C10 108.34(15) C6 C1 C14 113.68(16) C10 C1 C14 112.00(18) C6 C1 H1 107.0(12) C10 C1 H1 106.2(12) C14 C1 H1 109.2(12) O2 C2 O1 116.33(15) O2 C2 C3 126.35(16) O1 C2 C3 117.31(14) C4 C3 C2 120.92(16) C4 C3 H3 122.5(11) C2 C3 H3 116.4(11) C3 C4 C9 120.98(15) C3 C4 C13 118.88(15) C9 C4 C13 120.11(15) C6 C5 C9 121.79(16) C6 C5 H5 119.6(11) C9 C5 H5 118.6(11) C5 C6 C7 117.18(15) C5 C6 C1 123.78(16) C7 C6 C1 118.99(15) N1 C7 N2 116.36(15) N1 C7 C6 122.05(15) N2 C7 C6 121.59(15) N1 C8 O1 112.57(14) N1 C8 C9 126.49(15) O1 C8 C9 120.94(14) C8 C9 C5 114.60(15) C8 C9 C4 117.62(15) C5 C9 C4 127.77(15) C1 C10 C11 113.25(17) C1 C10 H10A 111.8(12) C11 C10 H10A 109.1(12) C1 C10 H10B 109.7(11) C11 C10 H10B 106.4(11) H10A C10 H10B 106.3(17) N2 C11 C15 111.58(17) N2 C11 C10 109.87(15) C15 C11 C10 110.87(18) N2 C11 H11 108.0(12) C15 C11 H11 108.1(12) C10 C11 H11 108.3(12) N2 C12 H12A 110.1(16) N2 C12 H12B 110(2) H12A C12 H12B 113(3) N2 C12 H12C 108(2) H12A C12 H12C 105(2) H12B C12 H12C 110(3) F1 C13 F3 106.80(15) F1 C13 F2 106.87(15) F3 C13 F2 106.39(15) F1 C13 C4 113.30(15) F3 C13 C4 112.38(15) F2 C13 C4 110.70(15) C1 C14 H14A 111.6(14) C1 C14 H14B 112.3(14) H14A C14 H14B 105.8(19) C1 C14 H14C 106.5(17) H14A C14 H14C 106(2) H14B C14 H14C 114(2) C11 C15 H15A 108.2(15) C11 C15 H15B 112.9(14) H15A C15 H15B 109(2) C11 C15 H15C 108.6(13) H15A C15 H15C 110(2) H15B C15 H15C 108.1(19) C8 N1 C7 117.77(14) C7 N2 C12 119.01(16) C7 N2 C11 122.92(15) C12 N2 C11 116.87(16) C8 O1 C2 122.22(13) loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_distance C6 C7 1.433(2) C7 N1 1.343(2) C8 N1 1.314(2) C8 C9 1.391(2) C5 C9 1.416(2) C5 C6 1.366(2) C8 O1 1.377(2) C2 O1 1.3820(19) C2 C3 1.435(2) C3 C4 1.354(2) C4 C9 1.434(2) C2 O2 1.215(2) C7 N2 1.356(2) C1 C6 1.513(2) C1 C10 1.514(3) C1 C14 1.518(3) C1 H1 1.05(2) C3 H3 0.954(19) C4 C13 1.502(2) C5 H5 0.936(19) C10 C11 1.519(3) C10 H10A 0.96(2) C10 H10B 1.04(2) C11 N2 1.475(2) C11 C15 1.517(3) C11 H11 1.03(2) C12 N2 1.464(3) C12 H12A 1.01(3) C12 H12B 0.96(4) C12 H12C 0.91(3) C13 F1 1.326(2) C13 F3 1.332(2) C13 F2 1.343(2) C14 H14A 0.99(3) C14 H14B 0.97(2) C14 H14C 1.03(3) C15 H15A 0.98(3) C15 H15B 1.00(3) C15 H15C 1.07(3) loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion C6 C7 N2 C11 -1.4(3) N1 C7 N2 C12 11.7(3) O2 C2 C3 C4 -177.94(17) O1 C2 C3 C4 0.8(2) C2 C3 C4 C9 -0.5(3) C2 C3 C4 C13 177.75(16) C9 C5 C6 C7 -2.2(2) C9 C5 C6 C1 175.43(17) C10 C1 C6 C5 149.84(17) C14 C1 C6 C5 24.6(3) C10 C1 C6 C7 -32.5(2) C14 C1 C6 C7 -157.71(18) C5 C6 C7 N1 3.8(2) C1 C6 C7 N1 -174.01(16) C5 C6 C7 N2 -175.99(15) C1 C6 C7 N2 6.2(3) N1 C8 C9 C5 2.4(2) O1 C8 C9 C5 -178.35(14) N1 C8 C9 C4 -178.67(15) O1 C8 C9 C4 0.6(2) C6 C5 C9 C8 -0.6(2) C6 C5 C9 C4 -179.36(16) C3 C4 C9 C8 -0.1(2) C13 C4 C9 C8 -178.40(15) C3 C4 C9 C5 178.59(16) C13 C4 C9 C5 0.3(3) C6 C1 C10 C11 55.8(2) C14 C1 C10 C11 -178.04(17) C1 C10 C11 N2 -51.8(2) C1 C10 C11 C15 -175.60(18) C3 C4 C13 F1 6.6(2) C9 C4 C13 F1 -175.14(15) C3 C4 C13 F3 127.75(17) C9 C4 C13 F3 -54.0(2) C3 C4 C13 F2 -113.45(18) C9 C4 C13 F2 64.8(2) O1 C8 N1 C7 179.68(14) C9 C8 N1 C7 -1.0(2) N2 C7 N1 C8 177.59(14) C6 C7 N1 C8 -2.2(2) C6 C7 N2 C12 -168.50(19) N1 C7 N2 C11 178.78(16) C15 C11 N2 C7 147.17(18) C10 C11 N2 C7 23.8(2) C15 C11 N2 C12 -45.5(3) C10 C11 N2 C12 -168.90(19) N1 C8 O1 C2 179.03(14) C9 C8 O1 C2 -0.3(2) O2 C2 O1 C8 178.48(15) C3 C2 O1 C8 -0.4(2) _cod_database_fobs_code 2104987 _journal_paper_doi 10.1107/S0108768111037311