data_2002926 _journal_name_full 'Acta Crystallographica, Section B' _journal_year 1999 _journal_volume B55 _journal_page_first 17 _journal_page_last 23 _publ_section_title ; Neutron Structures of Ammonium Fluoroberyllate ; loop_ _publ_author_name 'Srivastava, R. C.' 'Klooster, W. T.' 'Koetzle, T. F.' _chemical_name_systematic ; ammonium tetrafluoroberyllate ; _chemical_formula_sum 'Be F4 H8 N2' _chemical_formula_iupac '(N H4)2 Be F4' _chemical_formula_weight 121.093 _chemical_melting_point ? _symmetry_cell_setting 'orthorhombic' _symmetry_space_group_name_H-M 'P n a 21' _symmetry_space_group_name_Hall 'P 2c -2n' 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' _cell_length_a 15.017(6) _cell_length_b 5.876(3) _cell_length_c 10.418(4) _cell_angle_alpha 90.0 _cell_angle_beta 90.0 _cell_angle_gamma 90.0 _cell_volume 919.2(12) _cell_formula_units_Z 8 _cell_measurement_reflns_used 32 _cell_measurement_theta_min 20 _cell_measurement_theta_max 27 _cell_measurement_temperature 163 _exptl_crystal_description 'box' _exptl_crystal_colour 'colorless' _exptl_crystal_size_max 4.0 _exptl_crystal_size_mid 3.9 _exptl_crystal_size_min 3.9 _exptl_crystal_density_diffrn 1.750 _exptl_crystal_density_meas ? _exptl_crystal_density_method ? _exptl_crystal_F_000 ? _exptl_absorpt_coefficient_mu 0.291 _exptl_absorpt_correction_type analytical _exptl_absorpt_correction_T_min 0.346 _exptl_absorpt_correction_T_max 0.432 _diffrn_ambient_temperature 163 _diffrn_radiation_type 'neutron' _diffrn_radiation_wavelength 1.0462 _diffrn_radiation_source 'reactor' _diffrn_radiation_monochromator 'Be (002)' _diffrn_measurement_device 'beamline H6M, HFBR' _diffrn_measurement_method '\q/2\q' _diffrn_reflns_number 1972 _diffrn_reflns_av_R_equivalents ? _diffrn_reflns_av_sigmaI/netI ? _diffrn_reflns_theta_min 2 _diffrn_reflns_theta_max 55 _diffrn_reflns_limit_h_min 0 _diffrn_reflns_limit_h_max 23 _diffrn_reflns_limit_k_min 0 _diffrn_reflns_limit_k_max 9 _diffrn_reflns_limit_l_min 0 _diffrn_reflns_limit_l_max 16 _diffrn_reflns_reduction_process ? _diffrn_standards_number 2 _diffrn_standards_interval_count 100 _diffrn_standards_interval_time ? _diffrn_standards_decay_% 0 loop_ _diffrn_standard_refln_index_h _diffrn_standard_refln_index_k _diffrn_standard_refln_index_l 0 -4 0 0 -2 6 _reflns_number_total 1932 _reflns_number_observed 1390 _reflns_observed_criterion I>3\s _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.0476 _refine_ls_R_factor_obs 0.0476 _refine_ls_wR_factor_all 0.0552 _refine_ls_wR_factor_obs 0.0552 _refine_ls_goodness_of_fit_all 1.0650 _refine_ls_goodness_of_fit_obs 1.0650 _refine_ls_number_reflns 1932 _refine_ls_number_parameters 271 _refine_ls_number_restraints 0 _refine_ls_number_constraints 0 _refine_ls_hydrogen_treatment 'ref' _refine_ls_weighting_scheme 'w=1/[\s^2^(F)+0.0004F^2^]' _refine_ls_shift/esd_max .01 _refine_ls_shift/esd_mean ? _refine_diff_density_max '1.5 % of maximum' _refine_diff_density_min '1.5 % of maximum' _refine_ls_extinction_method 'type I, isotropic' _refine_ls_extinction_coef 390E1(10) _refine_ls_abs_structure_details ; ? ; _refine_ls_abs_structure_Flack ? loop_ _atom_type_symbol _atom_type_description _atom_type_scat_source H -3.7406 International_Tables_Vol_C Be 7.79 International_Tables_Vol_C N 9.36 International_Tables_Vol_C F 5.654 International_Tables_Vol_C 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_calc_flag _atom_site_calc_attached_atom _atom_site_type_symbol N11 0.2188(2) 0.2600(3) 0.0990 ? Uij ? ? N N12 0.4691(2) 0.2527(2) 0.39780(10) ? Uij ? ? N N21 0.3534(2) 0.2562(2) 0.8015(3) ? Uij ? ? N N22 0.6025(2) 0.2404(3) 0.6957(3) ? Uij ? ? N Be1 0.2509(2) 0.2536(3) 0.4161(3) ? Uij ? ? Be Be2 0.5008(2) 0.2553(3) 0.0785(4) ? Uij ? ? Be F11 0.1534(3) 0.2299(6) 0.3769(6) ? Uij ? ? F F12 0.2584(3) 0.2867(6) 0.5617(4) ? Uij ? ? F F13 0.2989(2) 0.0333(5) 0.3792(5) ? Uij ? ? F F14 0.2903(2) 0.4609(5) 0.3490(4) ? Uij ? ? F F21 0.4026(3) 0.2750(7) 0.1231(6) ? Uij ? ? F F22 0.5084(3) 0.2235(6) -0.0674(4) ? Uij ? ? F F23 0.5485(3) 0.4767(6) 0.1175(5) ? Uij ? ? F F24 0.5417(3) 0.0452(6) 0.1443(5) ? Uij ? ? F H111 0.2820(6) 0.2840(15) 0.1285(10) ? Uij ? ? H H112 0.1773(6) 0.2828(14) 0.1732(10) ? Uij ? ? H H113 0.2137(6) 0.0995(12) 0.0681(11) ? Uij ? ? H H114 0.2050(4) 0.3645(10) 0.0218(6) ? Uij ? ? H H121 0.5342(4) 0.2658(11) 0.3743(10) ? Uij ? ? H H122 0.4267(7) 0.2783(16) 0.3255(11) ? Uij ? ? H H123 0.4604(4) 0.0883(9) 0.4239(7) ? Uij ? ? H H124 0.4546(5) 0.3666(15) 0.4646(10) ? Uij ? ? H H211 0.3720(5) 0.2607(17) 0.7123(7) ? Uij ? ? H H212 0.4091(6) 0.2233(15) 0.8513(10) ? Uij ? ? H H213 0.3032(3) 0.1444(9) 0.8207(6) ? Uij ? ? H H214 0.3257(7) 0.4022(14) 0.8282(8) ? Uij ? ? H H221 0.6125(7) 0.2383(12) 0.7935(8) ? Uij ? ? H H222 0.6563(6) 0.2190(15) 0.6382(10) ? Uij ? ? H H223 0.5583(8) 0.1183(17) 0.6792(9) ? Uij ? ? H H224 0.5849(5) 0.4021(10) 0.6796(8) ? Uij ? ? H 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 N11 0.0129(9) 0.0124(8) 0.0146(8) -0.0008(4) 0.0010(8) -0.0006(5) N12 0.0131(9) 0.0153(8) 0.0201(9) 0.0000(4) 0.0000(9) -0.0005(5) N21 0.0115(8) 0.0161(9) 0.0148(9) -0.0001(4) 0.0037(7) -0.0006(5) N22 0.0191(10) 0.0119(9) 0.0147(9) -0.0025(4) 0.0018(8) 0.0002(5) Be1 0.0099(10) 0.0136(9) 0.0093(9) -0.0003(5) -0.0020(7) -0.0004(5) Be2 0.0115(11) 0.0086(8) 0.0156(11) -0.0001(5) -0.0025(8) 0.0005(5) F11 0.0122(13) 0.0308(14) 0.038(2) 0.0010(11) -0.0112(14) -0.0021(15) F12 0.0217(14) 0.0246(10) 0.0112(11) 0.0004(12) 0.0005(10) -0.0014(11) F13 0.0181(11) 0.0116(9) 0.0265(14) 0.0004(9) 0.0060(10) -0.0047(10) F14 0.0203(13) 0.0134(11) 0.0250(14) -0.0002(9) 0.0056(11) 0.0062(10) F21 0.0122(13) 0.0311(13) 0.0313(18) 0.0044(10) 0.0022(13) 0.0016(14) F22 0.0281(17) 0.0288(12) 0.0131(13) 0.0048(13) 0.0003(11) -0.0035(13) F23 0.0233(13) 0.0126(10) 0.0269(15) -0.0027(9) -0.0097(11) -0.0012(10) F24 0.0200(13) 0.0152(11) 0.0315(18) 0.0013(9) -0.0040(11) 0.0102(11) H111 0.040(4) 0.048(3) 0.051(4) -0.013(3) -0.021(3) 0.012(3) H112 0.048(4) 0.050(3) 0.040(4) -0.009(3) 0.024(3) -0.021(3) H113 0.048(4) 0.031(2) 0.075(5) -0.014(2) 0.014(4) -0.020(3) H114 0.034(3) 0.032(2) 0.028(2) 0.005(2) -0.008(2) 0.004(2) H121 0.014(2) 0.045(3) 0.050(3) -0.005(2) 0.005(2) -0.008(3) H122 0.044(4) 0.054(4) 0.048(4) 0.001(3) -0.025(4) 0.002(4) H123 0.041(3) 0.023(2) 0.035(3) -0.003(2) -0.002(2) 0.004(2) H124 0.036(3) 0.056(4) 0.062(5) 0.002(3) 0.001(3) -0.042(4) H211 0.037(2) 0.107(6) 0.014(2) -0.002(4) 0.012(2) -0.001(3) H212 0.026(3) 0.051(4) 0.043(3) 0.006(3) -0.004(2) 0.003(3) H213 0.018(2) 0.031(2) 0.037(2) -0.006(2) 0.006(2) 0.005(2) H214 0.097(6) 0.047(3) 0.033(3) 0.049(4) -0.002(4) -0.014(3) H221 0.078(5) 0.040(3) 0.024(3) -0.020(3) 0.003(3) 0.006(2) H222 0.032(3) 0.048(3) 0.042(4) 0.002(3) 0.018(3) -0.004(3) H223 0.079(5) 0.053(4) 0.045(4) -0.036(4) 0.006(4) 0.002(3) H224 0.058(4) 0.024(2) 0.065(4) 0.004(2) 0.008(3) -0.010(2)