#------------------------------------------------------------------------------
#$Date: 2016-03-25 10:01:37 +0200 (Fri, 25 Mar 2016) $
#$Revision: 179737 $
#$URL: svn://www.crystallography.net/cod/cif/7/00/33/7003315.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_7003315
loop_
_publ_author_name
'Lecren, Lollita'
'Roubeau, Olivier'
'Li, Yang-Guang'
'Le Goff, Xavier F.'
'Miyasaka, Hitoshi'
'Richard, Florent'
'Wernsdorfer, Wolfgang'
'Coulon, Claude'
'Clérac, Rodolphe'
_publ_section_title
;
 One-dimensional coordination polymers of antiferromagnetically-coupled
 [Mn4] single-molecule magnets
;
_journal_issue                   6
_journal_name_full               'Dalton Transactions'
_journal_page_first              755
_journal_page_last               766
_journal_paper_doi               10.1039/b715528j
_journal_year                    2008
_chemical_formula_sum            'C80 H84 Cl4 Mn8 N12 O38'
_chemical_formula_weight         2402.91
_chemical_name_common            catena-(Mn4(hmp)6(OOCCH3)2(ClO4)2)H2O
_chemical_name_systematic
;
?
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 101.30(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            1
_cell_length_a                   9.958(2)
_cell_length_b                   12.333(3)
_cell_length_c                   19.546(4)
_cell_measurement_temperature    100(2)
_cell_volume                     2353.9(9)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_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  0.0682
_diffrn_reflns_av_sigmaI/netI    0.0695
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            10542
_diffrn_reflns_theta_full        23.25
_diffrn_reflns_theta_max         23.25
_diffrn_reflns_theta_min         3.30
_exptl_absorpt_coefficient_mu    1.245
_exptl_absorpt_correction_T_max  0.87
_exptl_absorpt_correction_T_min  0.79
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   MULABS
_exptl_crystal_colour            red
_exptl_crystal_density_diffrn    1.695
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1220
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.947
_refine_diff_density_min         -0.957
_refine_diff_density_rms         0.084
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.019
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     361
_refine_ls_number_reflns         3356
_refine_ls_number_restraints     44
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0784
_refine_ls_R_factor_gt           0.0503
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[σ²(Fo²)+(0.0438P)²+5.8261P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1085
_refine_ls_wR_factor_ref         0.1224
_reflns_number_gt                2455
_reflns_number_total             3356
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b715528j.txt
_cod_data_source_block           ac3b
_cod_original_cell_volume        2354.0(9)
_cod_original_sg_symbol_H-M      P21/n
_cod_database_code               7003315
loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-x+1/2, y+1/2, -z+1/2'
'-x, -y, -z'
'x-1/2, -y-1/2, z-1/2'
loop_
_atom_site_label
_atom_site_type_symbol
_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
_atom_site_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_disorder_assembly
_atom_site_disorder_group
Mn2 Mn 0.50406(8) 0.87626(7) 0.02583(4) 0.0248(2) Uani 1 1 d . . .
Mn1 Mn 0.20431(8) 1.00661(7) -0.01161(4) 0.0246(2) Uani 1 1 d . . .
N1 N 0.2029(4) 1.1514(4) 0.0568(2) 0.0311(11) Uani 1 1 d . . .
N2 N 0.5091(5) 0.7150(4) -0.0228(3) 0.0346(12) Uani 1 1 d . . .
N3 N 0.4818(4) 0.8046(4) 0.1192(2) 0.0306(11) Uani 1 1 d . . .
O1 O 0.4277(3) 1.0357(3) 0.04745(17) 0.0251(8) Uani 1 1 d . . .
O2 O 0.3222(3) 0.8624(3) -0.02315(18) 0.0274(8) Uani 1 1 d . . .
O3 O 0.6821(3) 0.8929(3) 0.07519(18) 0.0292(9) Uani 1 1 d . . .
O100 O 0.1169(4) 0.9241(3) 0.06555(19) 0.0354(10) Uani 1 1 d . . .
O200 O 0.0550(4) 0.9936(3) -0.10222(19) 0.0336(9) Uani 1 1 d . . .
C1 C 0.1018(6) 1.2242(5) 0.0510(3) 0.0394(15) Uani 1 1 d . . .
H1 H 0.0274 1.2190 0.0125 0.047 Uiso 1 1 calc R . .
C2 C 0.1008(6) 1.3067(5) 0.0987(3) 0.0434(16) Uani 1 1 d . . .
H2 H 0.0279 1.3577 0.0927 0.052 Uiso 1 1 calc R . .
C3 C 0.2068(6) 1.3134(5) 0.1546(3) 0.0402(15) Uani 1 1 d . . .
H3 H 0.2070 1.3685 0.1886 0.048 Uiso 1 1 calc R . .
C4 C 0.3128(6) 1.2409(5) 0.1619(3) 0.0385(15) Uani 1 1 d . . .
H4 H 0.3875 1.2452 0.2004 0.046 Uiso 1 1 calc R . .
C5 C 0.3082(6) 1.1610(5) 0.1114(3) 0.0309(13) Uani 1 1 d . . .
C6 C 0.4240(6) 1.0796(5) 0.1146(3) 0.0328(14) Uani 1 1 d . . .
H6A H 0.5124 1.1157 0.1334 0.039 Uiso 1 1 calc R . .
H6B H 0.4119 1.0200 0.1468 0.039 Uiso 1 1 calc R . .
C7 C 0.6127(6) 0.6425(5) -0.0167(4) 0.0463(17) Uani 1 1 d . . .
H7 H 0.6956 0.6561 0.0155 0.056 Uiso 1 1 calc R . .
C8 C 0.6004(9) 0.5482(6) -0.0568(5) 0.064(2) Uani 1 1 d . . .
H8 H 0.6739 0.4979 -0.0522 0.077 Uiso 1 1 calc R . .
C9 C 0.4806(10) 0.5295(6) -0.1028(5) 0.070(2) Uani 1 1 d . . .
H9 H 0.4710 0.4666 -0.1315 0.084 Uiso 1 1 calc R . .
C10 C 0.3744(8) 0.6012(5) -0.1078(4) 0.0530(18) Uani 1 1 d . . .
H10 H 0.2899 0.5879 -0.1388 0.064 Uiso 1 1 calc R . .
C11 C 0.3922(6) 0.6927(5) -0.0671(3) 0.0363(14) Uani 1 1 d . . .
C12 C 0.2802(6) 0.7747(5) -0.0681(4) 0.0501(18) Uani 1 1 d . . .
H12A H 0.2502 0.8022 -0.1162 0.060 Uiso 1 1 calc R . .
H12B H 0.2008 0.7388 -0.0541 0.060 Uiso 1 1 calc R . .
C13 C 0.3725(6) 0.7505(5) 0.1328(3) 0.0361(14) Uani 1 1 d . . .
H13 H 0.2900 0.7509 0.0988 0.043 Uiso 1 1 calc R . .
C14 C 0.3755(6) 0.6946(5) 0.1941(3) 0.0418(16) Uani 1 1 d . . .
H14 H 0.2966 0.6580 0.2027 0.050 Uiso 1 1 calc R . .
C15 C 0.4965(7) 0.6934(5) 0.2426(3) 0.0438(16) Uani 1 1 d . . .
H15 H 0.5024 0.6550 0.2852 0.053 Uiso 1 1 calc R . .
C16 C 0.6092(6) 0.7486(5) 0.2288(3) 0.0416(15) Uani 1 1 d . . .
H16 H 0.6932 0.7482 0.2617 0.050 Uiso 1 1 calc R . .
C17 C 0.5984(5) 0.8041(4) 0.1666(3) 0.0298(13) Uani 1 1 d . . .
C18 C 0.7135(6) 0.8680(5) 0.1471(3) 0.0386(15) Uani 1 1 d . . .
H18A H 0.7274 0.9358 0.1747 0.046 Uiso 1 1 calc R . .
H18B H 0.7992 0.8253 0.1577 0.046 Uiso 1 1 calc R . .
C100 C 0.0574(5) 0.9575(4) 0.1128(3) 0.0264(13) Uani 1 1 d . . .
C101 C 0.1251(6) 0.9359(6) 0.1869(3) 0.0447(16) Uani 1 1 d . . .
H10A H 0.0689 0.9660 0.2182 0.067 Uiso 1 1 calc R . .
H10B H 0.2157 0.9700 0.1966 0.067 Uiso 1 1 calc R . .
H10C H 0.1349 0.8575 0.1944 0.067 Uiso 1 1 calc R . .
Cl1 Cl 0.9568(2) 0.5863(2) 0.17321(16) 0.0971(9) Uani 1 1 d . . .
O11 O 0.8463(13) 0.5953(14) 0.2101(8) 0.145(5) Uani 0.60 1 d PDU A 1
O12 O 1.0033(13) 0.6979(9) 0.1582(8) 0.132(5) Uani 0.60 1 d PDU A 1
O13 O 1.0675(18) 0.5286(15) 0.2101(9) 0.088(5) Uani 0.60 1 d PDU A 1
O14 O 0.9102(13) 0.5392(11) 0.1045(7) 0.094(4) Uani 0.60 1 d PU A 1
O21 O 0.898(3) 0.486(2) 0.2130(14) 0.170(7) Uani 0.40 1 d PDU A 2
O22 O 0.934(2) 0.6717(17) 0.2176(14) 0.133(6) Uani 0.40 1 d PDU A 2
O23 O 1.089(3) 0.566(3) 0.1875(19) 0.118(8) Uani 0.40 1 d PDU A 2
O24 O 0.874(2) 0.5861(18) 0.1118(13) 0.103(6) Uani 0.40 1 d PU A 2
O2W O 1.1138(15) 0.5884(14) 0.0298(11) 0.164(8) Uani 0.50 1 d P . .
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'
N N 0.0061 0.0033 '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'
Cl Cl 0.1484 0.1585 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
Mn Mn 0.3368 0.7283 '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
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
O3 Mn2 O2 178.59(17) . . ?
O3 Mn2 O1 83.64(15) . 3_675 ?
O2 Mn2 O1 96.43(15) . 3_675 ?
O3 Mn2 N3 81.15(17) . . ?
O2 Mn2 N3 98.65(17) . . ?
O1 Mn2 N3 163.87(17) 3_675 . ?
O3 Mn2 O1 97.66(15) . . ?
O2 Mn2 O1 80.97(14) . . ?
O1 Mn2 O1 80.27(13) 3_675 . ?
N3 Mn2 O1 96.45(15) . . ?
O3 Mn2 N2 102.92(17) . . ?
O2 Mn2 N2 78.47(16) . . ?
O1 Mn2 N2 98.02(15) 3_675 . ?
N3 Mn2 N2 90.59(18) . . ?
O1 Mn2 N2 159.05(16) . . ?
O3 Mn2 Mn2 91.20(12) . 3_675 ?
O2 Mn2 Mn2 87.92(11) . 3_675 ?
O1 Mn2 Mn2 41.99(10) 3_675 3_675 ?
N3 Mn2 Mn2 132.85(13) . 3_675 ?
O1 Mn2 Mn2 38.28(9) . 3_675 ?
N2 Mn2 Mn2 136.19(13) . 3_675 ?
O200 Mn1 O100 103.98(15) . . ?
O200 Mn1 O2 99.16(14) . . ?
O100 Mn1 O2 89.23(14) . . ?
O200 Mn1 O3 85.64(13) . 3_675 ?
O100 Mn1 O3 169.63(14) . 3_675 ?
O2 Mn1 O3 93.10(13) . 3_675 ?
O200 Mn1 N1 118.90(16) . . ?
O100 Mn1 N1 84.68(15) . . ?
O2 Mn1 N1 141.82(16) . . ?
O3 Mn1 N1 87.26(15) 3_675 . ?
O200 Mn1 O1 152.63(13) . . ?
O100 Mn1 O1 101.84(13) . . ?
O2 Mn1 O1 72.15(12) . . ?
O3 Mn1 O1 69.40(12) 3_675 . ?
N1 Mn1 O1 72.35(14) . . ?
C1 N1 C5 117.6(5) . . ?
C1 N1 Mn1 125.5(4) . . ?
C5 N1 Mn1 116.7(4) . . ?
C11 N2 C7 118.2(5) . . ?
C11 N2 Mn2 112.0(4) . . ?
C7 N2 Mn2 129.7(4) . . ?
C17 N3 C13 119.1(5) . . ?
C17 N3 Mn2 112.6(3) . . ?
C13 N3 Mn2 127.8(4) . . ?
C6 O1 Mn2 121.5(3) . 3_675 ?
C6 O1 Mn2 126.4(3) . . ?
Mn2 O1 Mn2 99.73(13) 3_675 . ?
C6 O1 Mn1 108.7(3) . . ?
Mn2 O1 Mn1 98.81(14) 3_675 . ?
Mn2 O1 Mn1 95.77(13) . . ?
C12 O2 Mn2 121.7(3) . . ?
C12 O2 Mn1 126.6(3) . . ?
Mn2 O2 Mn1 111.06(16) . . ?
C18 O3 Mn2 119.7(3) . . ?
C18 O3 Mn1 129.9(3) . 3_675 ?
Mn2 O3 Mn1 108.11(16) . 3_675 ?
C100 O100 Mn1 132.5(4) . . ?
C100 O200 Mn1 124.7(3) 3_575 . ?
N1 C1 C2 122.9(6) . . ?
N1 C1 H1 118.5 . . ?
C2 C1 H1 118.5 . . ?
C3 C2 C1 118.5(6) . . ?
C3 C2 H2 120.7 . . ?
C1 C2 H2 120.7 . . ?
C2 C3 C4 120.2(6) . . ?
C2 C3 H3 119.9 . . ?
C4 C3 H3 119.9 . . ?
C3 C4 C5 118.1(6) . . ?
C3 C4 H4 120.9 . . ?
C5 C4 H4 120.9 . . ?
N1 C5 C4 122.5(5) . . ?
N1 C5 C6 116.2(5) . . ?
C4 C5 C6 121.3(5) . . ?
O1 C6 C5 111.6(4) . . ?
O1 C6 H6A 109.3 . . ?
C5 C6 H6A 109.3 . . ?
O1 C6 H6B 109.3 . . ?
C5 C6 H6B 109.3 . . ?
H6A C6 H6B 108.0 . . ?
N2 C7 C8 121.3(7) . . ?
N2 C7 H7 119.3 . . ?
C8 C7 H7 119.3 . . ?
C9 C8 C7 118.7(7) . . ?
C9 C8 H8 120.6 . . ?
C7 C8 H8 120.6 . . ?
C8 C9 C10 120.0(7) . . ?
C8 C9 H9 120.0 . . ?
C10 C9 H9 120.0 . . ?
C9 C10 C11 118.8(7) . . ?
C9 C10 H10 120.6 . . ?
C11 C10 H10 120.6 . . ?
N2 C11 C10 122.9(6) . . ?
N2 C11 C12 114.7(5) . . ?
C10 C11 C12 122.4(6) . . ?
O2 C12 C11 112.5(5) . . ?
O2 C12 H12A 109.1 . . ?
C11 C12 H12A 109.1 . . ?
O2 C12 H12B 109.1 . . ?
C11 C12 H12B 109.1 . . ?
H12A C12 H12B 107.8 . . ?
N3 C13 C14 122.6(6) . . ?
N3 C13 H13 118.7 . . ?
C14 C13 H13 118.7 . . ?
C13 C14 C15 118.1(6) . . ?
C13 C14 H14 121.0 . . ?
C15 C14 H14 121.0 . . ?
C14 C15 C16 119.5(6) . . ?
C14 C15 H15 120.2 . . ?
C16 C15 H15 120.2 . . ?
C17 C16 C15 119.3(6) . . ?
C17 C16 H16 120.4 . . ?
C15 C16 H16 120.4 . . ?
N3 C17 C16 121.4(5) . . ?
N3 C17 C18 115.1(5) . . ?
C16 C17 C18 123.5(5) . . ?
O3 C18 C17 109.6(4) . . ?
O3 C18 H18A 109.7 . . ?
C17 C18 H18A 109.7 . . ?
O3 C18 H18B 109.7 . . ?
C17 C18 H18B 109.7 . . ?
H18A C18 H18B 108.2 . . ?
O200 C100 O100 124.7(5) 3_575 . ?
O200 C100 C101 117.6(5) 3_575 . ?
O100 C100 C101 117.6(5) . . ?
C100 C101 H10A 109.5 . . ?
C100 C101 H10B 109.5 . . ?
H10A C101 H10B 109.5 . . ?
C100 C101 H10C 109.5 . . ?
H10A C101 H10C 109.5 . . ?
H10B C101 H10C 109.5 . . ?
O23 Cl1 O24 128(2) . . ?
O24 Cl1 O13 139.9(13) . . ?
O23 Cl1 O22 107(2) . . ?
O24 Cl1 O22 114.5(13) . . ?
O13 Cl1 O22 105.6(13) . . ?
O23 Cl1 O11 138.0(16) . . ?
O24 Cl1 O11 92.9(12) . . ?
O13 Cl1 O11 112.8(8) . . ?
O22 Cl1 O11 53.2(10) . . ?
O23 Cl1 O14 104.2(19) . . ?
O13 Cl1 O14 110.6(10) . . ?
O22 Cl1 O14 143.8(10) . . ?
O11 Cl1 O14 111.0(9) . . ?
O23 Cl1 O12 83.2(14) . . ?
O24 Cl1 O12 89.3(12) . . ?
O13 Cl1 O12 109.1(9) . . ?
O22 Cl1 O12 61.8(11) . . ?
O11 Cl1 O12 108.9(8) . . ?
O14 Cl1 O12 104.0(9) . . ?
O23 Cl1 O21 101.1(13) . . ?
O24 Cl1 O21 102.2(14) . . ?
O13 Cl1 O21 71.7(12) . . ?
O22 Cl1 O21 99.1(13) . . ?
O11 Cl1 O21 55.7(10) . . ?
O14 Cl1 O21 93.3(11) . . ?
O12 Cl1 O21 160.7(11) . . ?
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
Mn2 O3 1.856(3) . ?
Mn2 O2 1.883(3) . ?
Mn2 O1 2.018(3) 3_675 ?
Mn2 N3 2.078(4) . ?
Mn2 O1 2.180(4) . ?
Mn2 N2 2.209(5) . ?
Mn2 Mn2 3.2110(17) 3_675 ?
Mn1 O200 2.084(4) . ?
Mn1 O100 2.140(4) . ?
Mn1 O2 2.167(4) . ?
Mn1 O3 2.216(4) 3_675 ?
Mn1 N1 2.232(4) . ?
Mn1 O1 2.324(4) . ?
N1 C1 1.337(7) . ?
N1 C5 1.347(7) . ?
N2 C11 1.336(7) . ?
N2 C7 1.353(7) . ?
N3 C17 1.336(7) . ?
N3 C13 1.347(7) . ?
O1 C6 1.427(6) . ?
O1 Mn2 2.018(3) 3_675 ?
O2 C12 1.405(7) . ?
O3 C18 1.413(6) . ?
O3 Mn1 2.216(4) 3_675 ?
O100 C100 1.260(6) . ?
O200 C100 1.252(6) 3_575 ?
C1 C2 1.380(8) . ?
C1 H1 0.9500 . ?
C2 C3 1.366(8) . ?
C2 H2 0.9500 . ?
C3 C4 1.369(8) . ?
C3 H3 0.9500 . ?
C4 C5 1.390(8) . ?
C4 H4 0.9500 . ?
C5 C6 1.521(8) . ?
C6 H6A 0.9900 . ?
C6 H6B 0.9900 . ?
C7 C8 1.394(10) . ?
C7 H7 0.9500 . ?
C8 C9 1.366(11) . ?
C8 H8 0.9500 . ?
C9 C10 1.367(10) . ?
C9 H9 0.9500 . ?
C10 C11 1.371(8) . ?
C10 H10 0.9500 . ?
C11 C12 1.503(8) . ?
C12 H12A 0.9900 . ?
C12 H12B 0.9900 . ?
C13 C14 1.377(8) . ?
C13 H13 0.9500 . ?
C14 C15 1.379(9) . ?
C14 H14 0.9500 . ?
C15 C16 1.384(8) . ?
C15 H15 0.9500 . ?
C16 C17 1.380(8) . ?
C16 H16 0.9500 . ?
C17 C18 1.501(8) . ?
C18 H18A 0.9900 . ?
C18 H18B 0.9900 . ?
C100 O200 1.252(6) 3_575 ?
C100 C101 1.497(8) . ?
C101 H10A 0.9800 . ?
C101 H10B 0.9800 . ?
C101 H10C 0.9800 . ?
Cl1 O23 1.31(3) . ?
Cl1 O24 1.32(2) . ?
Cl1 O13 1.389(15) . ?
Cl1 O22 1.41(2) . ?
Cl1 O11 1.433(12) . ?
Cl1 O14 1.453(12) . ?
Cl1 O12 1.499(12) . ?
Cl1 O21 1.63(3) . ?
