# Supplementary Material (ESI) for Dalton Transactions
# This journal is (c) The Royal Society of Chemistry 2008

data_global
_journal_name_full               'Dalton Trans.'

_journal_coden_Cambridge         0222

_publ_contact_author_name        'Tristram Chivers'
_publ_contact_author_email       CHIVERS@UCALGARY.CA

_publ_section_title              
;
Formation and X-ray structure of a seven-membered
C4OBN heterocycle by a THF ring-expansion process
;
loop_
_publ_author_name
'Tristram Chivers'
'Andrea M Corrente'

# Attachment 'C4OBN_cmpd_1a.cif'

data_amc703
_database_code_depnum_ccdc_archive 'CCDC 692058'

_audit_creation_method           SHELXL-97
_chemical_name_systematic        
;
?
;
_chemical_name_common            ?
_chemical_melting_point          ?
_chemical_formula_moiety         'C28 H43 B N2 O'
_chemical_formula_sum            'C28 H43 B N2 O'
_chemical_formula_weight         434.45

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'
B B 0.0013 0.0007 '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'

_symmetry_cell_setting           Monoclinic
_symmetry_space_group_name_H-M   P2(1)/n

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'

_cell_length_a                   10.839(2)
_cell_length_b                   20.360(4)
_cell_length_c                   12.049(2)
_cell_angle_alpha                90.00
_cell_angle_beta                 97.85(3)
_cell_angle_gamma                90.00
_cell_volume                     2633.8(9)
_cell_formula_units_Z            4
_cell_measurement_temperature    173(2)
_cell_measurement_reflns_used    26111
_cell_measurement_theta_min      2.57
_cell_measurement_theta_max      25.03

_exptl_crystal_description       block
_exptl_crystal_colour            colourless
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.24
_exptl_crystal_density_meas      ?
_exptl_crystal_density_diffrn    1.096
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             952
_exptl_absorpt_coefficient_mu    0.065
_exptl_absorpt_correction_type   Integration
_exptl_absorpt_correction_T_min  0.9821
_exptl_absorpt_correction_T_max  0.9846
_exptl_absorpt_process_details   'HKL Scalepack (Otwinowski and Minor 1997)'

_exptl_special_details           
;
?
;

_diffrn_ambient_temperature      173(2)
_diffrn_radiation_wavelength     0.71073
_diffrn_radiation_type           MoK\a
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_monochromator  graphite
_diffrn_measurement_device_type  'Nonius Kappa CCD'
_diffrn_measurement_method       'phi\omega scans'
_diffrn_detector_area_resol_mean ?
_diffrn_standards_number         ?
_diffrn_standards_interval_count ?
_diffrn_standards_interval_time  ?
_diffrn_standards_decay_%        ?
_diffrn_reflns_number            26111
_diffrn_reflns_av_R_equivalents  0.0278
_diffrn_reflns_av_sigmaI/netI    0.0372
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_theta_min         2.57
_diffrn_reflns_theta_max         25.03
_reflns_number_total             4634
_reflns_number_gt                3528
_reflns_threshold_expression     >2sigma(I)

_computing_data_collection       'Nonius COLLECT'
_computing_cell_refinement       'Nonius DENZO'
_computing_data_reduction        'Nonius DENZO'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'

_refine_special_details          
;
Refinement of F^2^ against ALL reflections. The weighted R-factor wR and
goodness of fit S are based on F^2^, conventional R-factors R are based
on F, with F set to zero for negative F^2^. The threshold expression of
F^2^ > 2sigma(F^2^) is used only for calculating R-factors(gt) etc. and is
not relevant to the choice of reflections for refinement. R-factors based
on F^2^ are statistically about twice as large as those based on F, and R-
factors based on ALL data will be even larger.
;

_refine_ls_structure_factor_coef Fsqd
_refine_ls_matrix_type           full
_refine_ls_weighting_scheme      calc
_refine_ls_weighting_details     
'calc w=1/[\s^2^(Fo^2^)+(0.0865P)^2^+1.1176P] where P=(Fo^2^+2Fc^2^)/3'
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_atom_sites_solution_hydrogens   geom
_refine_ls_hydrogen_treatment    constr
_refine_ls_extinction_method     SHELXL
_refine_ls_extinction_coef       0.048(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_number_reflns         4634
_refine_ls_number_parameters     284
_refine_ls_number_restraints     6
_refine_ls_R_factor_all          0.0802
_refine_ls_R_factor_gt           0.0597
_refine_ls_wR_factor_ref         0.1671
_refine_ls_wR_factor_gt          0.1515
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_restrained_S_all      1.076
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.001

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
B1 B 0.1253(2) 0.68688(11) 0.63248(18) 0.0284(5) Uani 1 1 d . A .
O1 O 0.17631(15) 0.73276(7) 0.70990(11) 0.0394(4) Uani 1 1 d . . .
N1 N 0.06738(15) 0.70414(8) 0.52280(13) 0.0279(4) Uani 1 1 d . . .
C1 C 0.02974(17) 0.65422(9) 0.44043(15) 0.0264(4) Uani 1 1 d . A .
C2 C -0.08207(18) 0.61950(10) 0.44231(15) 0.0293(5) Uani 1 1 d . . .
C3 C -0.11751(19) 0.57325(10) 0.35865(17) 0.0349(5) Uani 1 1 d . A .
H3A H -0.1926 0.5493 0.3595 0.042 Uiso 1 1 calc R . .
C4 C -0.0454(2) 0.56153(10) 0.27436(17) 0.0376(5) Uani 1 1 d . . .
H4A H -0.0718 0.5306 0.2169 0.045 Uiso 1 1 calc R A .
C5 C 0.0651(2) 0.59510(10) 0.27453(17) 0.0359(5) Uani 1 1 d . A .
H5A H 0.1150 0.5863 0.2173 0.043 Uiso 1 1 calc R . .
C6 C 0.10546(18) 0.64143(9) 0.35619(15) 0.0285(5) Uani 1 1 d . . .
C7 C 0.22689(19) 0.67788(10) 0.35120(17) 0.0341(5) Uani 1 1 d . A .
H7A H 0.2449 0.7051 0.4206 0.041 Uiso 1 1 calc R . .
C8 C 0.2154(2) 0.72426(13) 0.2504(2) 0.0513(6) Uani 1 1 d . . .
H8A H 0.1455 0.7544 0.2537 0.077 Uiso 1 1 calc R A .
H8B H 0.2008 0.6986 0.1810 0.077 Uiso 1 1 calc R . .
H8C H 0.2925 0.7495 0.2518 0.077 Uiso 1 1 calc R . .
C9 C 0.3361(2) 0.63077(13) 0.3476(2) 0.0523(6) Uani 1 1 d . . .
H9A H 0.3412 0.6005 0.4114 0.078 Uiso 1 1 calc R A .
H9B H 0.4137 0.6559 0.3516 0.078 Uiso 1 1 calc R . .
H9C H 0.3234 0.6057 0.2776 0.078 Uiso 1 1 calc R . .
C10 C -0.16744(18) 0.63268(11) 0.53034(17) 0.0356(5) Uani 1 1 d . A .
H10A H -0.1196 0.6595 0.5912 0.043 Uiso 1 1 calc R . .
C11 C -0.2082(2) 0.56950(13) 0.5834(2) 0.0524(7) Uani 1 1 d . . .
H11A H -0.1346 0.5435 0.6119 0.079 Uiso 1 1 calc R A .
H11B H -0.2618 0.5440 0.5270 0.079 Uiso 1 1 calc R . .
H11C H -0.2545 0.5805 0.6453 0.079 Uiso 1 1 calc R . .
C12 C -0.2807(2) 0.67283(13) 0.4807(2) 0.0488(6) Uani 1 1 d . . .
H12A H -0.2529 0.7134 0.4480 0.073 Uiso 1 1 calc R A .
H12B H -0.3310 0.6837 0.5398 0.073 Uiso 1 1 calc R . .
H12C H -0.3310 0.6471 0.4223 0.073 Uiso 1 1 calc R . .
N2 N 0.13201(14) 0.62019(8) 0.66754(12) 0.0271(4) Uani 1 1 d . . .
H1D H 0.0982 0.5909 0.6189 0.033 Uiso 1 1 calc R A .
C13 C 0.18829(17) 0.59589(9) 0.77401(15) 0.0269(4) Uani 1 1 d . A .
C14 C 0.30656(18) 0.56602(10) 0.78317(16) 0.0305(5) Uani 1 1 d . . .
C15 C 0.3570(2) 0.53933(11) 0.88540(18) 0.0392(5) Uani 1 1 d . A .
H15A H 0.4359 0.5184 0.8921 0.047 Uiso 1 1 calc R . .
C16 C 0.2940(2) 0.54281(12) 0.97762(18) 0.0448(6) Uani 1 1 d . . .
H16A H 0.3295 0.5243 1.0471 0.054 Uiso 1 1 calc R A .
C17 C 0.1796(2) 0.57328(11) 0.96837(17) 0.0406(5) Uani 1 1 d . A .
H17A H 0.1378 0.5762 1.0326 0.049 Uiso 1 1 calc R . .
C18 C 0.12361(19) 0.59985(9) 0.86753(16) 0.0307(5) Uani 1 1 d . . .
C19 C -0.00508(19) 0.63037(11) 0.86190(17) 0.0352(5) Uani 1 1 d . A .
H19A H -0.0321 0.6442 0.7827 0.042 Uiso 1 1 calc R . .
C20 C -0.0029(2) 0.69112(13) 0.9351(2) 0.0555(7) Uani 1 1 d . . .
H20A H 0.0534 0.7238 0.9098 0.083 Uiso 1 1 calc R A .
H20B H 0.0263 0.6792 1.0131 0.083 Uiso 1 1 calc R . .
H20C H -0.0870 0.7095 0.9298 0.083 Uiso 1 1 calc R . .
C21 C -0.1013(2) 0.58119(13) 0.8941(2) 0.0527(6) Uani 1 1 d . . .
H21A H -0.1835 0.6020 0.8860 0.079 Uiso 1 1 calc R A .
H21B H -0.0778 0.5673 0.9720 0.079 Uiso 1 1 calc R . .
H21C H -0.1040 0.5428 0.8448 0.079 Uiso 1 1 calc R . .
C22 C 0.37911(19) 0.56567(10) 0.68350(18) 0.0361(5) Uani 1 1 d . A .
H22A H 0.3173 0.5624 0.6141 0.043 Uiso 1 1 calc R . .
C23 C 0.4481(2) 0.63094(12) 0.6784(2) 0.0533(7) Uani 1 1 d . . .
H23A H 0.3890 0.6673 0.6793 0.080 Uiso 1 1 calc R A .
H23B H 0.4865 0.6328 0.6094 0.080 Uiso 1 1 calc R . .
H23C H 0.5129 0.6345 0.7434 0.080 Uiso 1 1 calc R . .
C24 C 0.46968(19) 0.50845(10) 0.68255(15) 0.0480(6) Uani 1 1 d . . .
H24A H 0.4259 0.4671 0.6916 0.072 Uiso 1 1 calc R A .
H24B H 0.5379 0.5136 0.7443 0.072 Uiso 1 1 calc R . .
H24C H 0.5035 0.5079 0.6111 0.072 Uiso 1 1 calc R . .
C28 C 0.0157(2) 0.76989(10) 0.49220(15) 0.0488(6) Uiso 0.600(6) 1 d PRD A 1
H28C H -0.0205 0.7681 0.4122 0.059 Uiso 0.600(6) 1 calc PR A 1
H28D H -0.0543 0.7772 0.5357 0.059 Uiso 0.600(6) 1 calc PR A 1
C27 C 0.0954(3) 0.82809(18) 0.5069(3) 0.0399(11) Uiso 0.600(6) 1 d PD A 1
H27A H 0.0445 0.8665 0.4790 0.048 Uiso 0.600(6) 1 calc PR A 1
H27B H 0.1614 0.8230 0.4582 0.048 Uiso 0.600(6) 1 calc PR A 1
C26 C 0.1592(5) 0.8443(2) 0.6261(4) 0.0446(14) Uiso 0.600(6) 1 d PD A 1
H26A H 0.2119 0.8838 0.6232 0.053 Uiso 0.600(6) 1 calc PR A 1
H26B H 0.0947 0.8545 0.6742 0.053 Uiso 0.600(6) 1 calc PR A 1
C25 C 0.2353(2) 0.79066(11) 0.6752(2) 0.0447(6) Uiso 0.600(6) 1 d PD A 1
H25A H 0.2906 0.7771 0.6203 0.054 Uiso 0.600(6) 1 calc PR A 1
H25D H 0.2895 0.8082 0.7414 0.054 Uiso 0.600(6) 1 calc PR A 1
C27A C 0.0133(5) 0.8171(3) 0.5788(5) 0.0488(18) Uiso 0.400(6) 1 d PD A 2
H27D H -0.0369 0.7980 0.6336 0.059 Uiso 0.400(6) 1 calc PR A 2
H27C H -0.0336 0.8555 0.5449 0.059 Uiso 0.400(6) 1 calc PR A 2
C26A C 0.1290(6) 0.8425(3) 0.6434(7) 0.044(2) Uiso 0.400(6) 1 d PD A 2
H26C H 0.1080 0.8625 0.7134 0.053 Uiso 0.400(6) 1 calc PR A 2
H26D H 0.1619 0.8779 0.5993 0.053 Uiso 0.400(6) 1 calc PR A 2
C28A C 0.0157(2) 0.76989(10) 0.49220(15) 0.0488(6) Uiso 0.400(6) 1 d PD A 2
H28A H 0.0640 0.7888 0.4359 0.059 Uiso 0.400(6) 1 calc PR A 2
H28B H -0.0708 0.7639 0.4550 0.059 Uiso 0.400(6) 1 calc PR A 2
C25A C 0.2353(2) 0.79066(11) 0.6752(2) 0.0447(6) Uiso 0.400(6) 1 d PD A 2
H25B H 0.2785 0.7811 0.6097 0.054 Uiso 0.400(6) 1 calc PR A 2
H25C H 0.2972 0.8074 0.7367 0.054 Uiso 0.400(6) 1 calc PR A 2

loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_23
_atom_site_aniso_U_13
_atom_site_aniso_U_12
B1 0.0307(12) 0.0303(12) 0.0257(11) -0.0020(9) 0.0095(9) -0.0011(9)
O1 0.0595(10) 0.0309(8) 0.0269(7) -0.0009(6) 0.0026(7) -0.0099(7)
N1 0.0331(9) 0.0255(8) 0.0250(8) -0.0002(7) 0.0041(7) 0.0009(7)
C1 0.0293(10) 0.0261(10) 0.0226(9) 0.0022(8) -0.0007(8) 0.0023(8)
C2 0.0293(10) 0.0315(10) 0.0264(10) 0.0039(8) 0.0010(8) 0.0023(8)
C3 0.0330(11) 0.0348(11) 0.0356(11) 0.0019(9) -0.0006(9) -0.0043(9)
C4 0.0455(13) 0.0326(11) 0.0335(11) -0.0070(9) 0.0011(9) -0.0021(10)
C5 0.0426(12) 0.0368(12) 0.0295(11) -0.0038(9) 0.0099(9) 0.0019(9)
C6 0.0325(10) 0.0288(10) 0.0242(9) 0.0019(8) 0.0039(8) 0.0022(8)
C7 0.0347(11) 0.0396(12) 0.0295(10) -0.0021(9) 0.0092(9) -0.0036(9)
C8 0.0542(15) 0.0536(15) 0.0465(13) 0.0121(12) 0.0087(12) -0.0122(12)
C9 0.0380(13) 0.0602(16) 0.0601(16) -0.0033(13) 0.0115(11) 0.0034(12)
C10 0.0285(11) 0.0467(13) 0.0318(11) 0.0011(9) 0.0050(9) -0.0025(9)
C11 0.0453(14) 0.0666(17) 0.0477(14) 0.0148(13) 0.0147(11) -0.0051(12)
C12 0.0400(13) 0.0608(16) 0.0472(14) 0.0027(12) 0.0122(11) 0.0105(11)
N2 0.0315(9) 0.0279(8) 0.0213(8) -0.0012(7) 0.0007(6) -0.0031(7)
C13 0.0303(10) 0.0243(10) 0.0255(10) 0.0000(8) 0.0019(8) -0.0046(8)
C14 0.0284(10) 0.0298(10) 0.0327(11) 0.0001(8) 0.0026(8) -0.0030(8)
C15 0.0325(11) 0.0440(13) 0.0398(12) 0.0063(10) 0.0004(9) 0.0035(10)
C16 0.0464(13) 0.0540(14) 0.0317(11) 0.0104(11) -0.0024(10) 0.0036(11)
C17 0.0461(13) 0.0492(13) 0.0273(11) 0.0036(10) 0.0080(9) 0.0021(11)
C18 0.0348(11) 0.0301(10) 0.0270(10) 0.0004(8) 0.0038(8) -0.0027(8)
C19 0.0363(11) 0.0408(12) 0.0297(10) 0.0001(9) 0.0086(9) 0.0019(9)
C20 0.0501(15) 0.0478(14) 0.0684(17) -0.0132(13) 0.0073(13) 0.0061(12)
C21 0.0399(13) 0.0530(15) 0.0679(17) -0.0020(13) 0.0169(12) -0.0037(11)
C22 0.0307(11) 0.0420(12) 0.0364(11) 0.0005(9) 0.0079(9) 0.0002(9)
C23 0.0464(14) 0.0501(14) 0.0685(16) 0.0050(13) 0.0269(12) -0.0064(12)
C24 0.0392(13) 0.0520(14) 0.0549(14) -0.0032(12) 0.0137(11) 0.0048(11)

_geom_special_details            
;
All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds involving l.s. planes.
;

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
B1 O1 1.381(3) . ?
B1 N2 1.421(3) . ?
B1 N1 1.428(3) . ?
O1 C25 1.431(3) . ?
N1 C1 1.440(2) . ?
N1 C28 1.478(2) . ?
C1 C2 1.406(3) . ?
C1 C6 1.414(3) . ?
C2 C3 1.394(3) . ?
C2 C10 1.524(3) . ?
C3 C4 1.384(3) . ?
C4 C5 1.379(3) . ?
C5 C6 1.390(3) . ?
C6 C7 1.519(3) . ?
C7 C9 1.528(3) . ?
C7 C8 1.530(3) . ?
C10 C12 1.527(3) . ?
C10 C11 1.528(3) . ?
N2 C13 1.431(2) . ?
C13 C18 1.408(3) . ?
C13 C14 1.409(3) . ?
C14 C15 1.388(3) . ?
C14 C22 1.523(3) . ?
C15 C16 1.383(3) . ?
C16 C17 1.377(3) . ?
C17 C18 1.391(3) . ?
C18 C19 1.520(3) . ?
C19 C20 1.518(3) . ?
C19 C21 1.533(3) . ?
C22 C24 1.525(3) . ?
C22 C23 1.530(3) . ?
C28 C27 1.463(4) . ?
C27 C26 1.541(5) . ?
C26 C25 1.445(5) . ?
C27A C26A 1.477(7) . ?

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
O1 B1 N2 116.50(18) . . ?
O1 B1 N1 122.94(18) . . ?
N2 B1 N1 120.56(18) . . ?
B1 O1 C25 120.89(16) . . ?
B1 N1 C1 120.77(16) . . ?
B1 N1 C28 123.89(16) . . ?
C1 N1 C28 113.91(15) . . ?
C2 C1 C6 120.34(17) . . ?
C2 C1 N1 120.50(16) . . ?
C6 C1 N1 119.15(16) . . ?
C3 C2 C1 118.74(18) . . ?
C3 C2 C10 119.25(18) . . ?
C1 C2 C10 121.97(17) . . ?
C4 C3 C2 121.29(19) . . ?
C5 C4 C3 119.40(19) . . ?
C4 C5 C6 121.78(18) . . ?
C5 C6 C1 118.42(18) . . ?
C5 C6 C7 119.60(17) . . ?
C1 C6 C7 121.97(17) . . ?
C6 C7 C9 111.90(18) . . ?
C6 C7 C8 110.84(17) . . ?
C9 C7 C8 110.13(19) . . ?
C2 C10 C12 110.71(17) . . ?
C2 C10 C11 112.38(18) . . ?
C12 C10 C11 110.56(18) . . ?
B1 N2 C13 126.50(16) . . ?
C18 C13 C14 120.59(17) . . ?
C18 C13 N2 119.97(17) . . ?
C14 C13 N2 119.41(16) . . ?
C15 C14 C13 118.80(18) . . ?
C15 C14 C22 121.00(18) . . ?
C13 C14 C22 120.16(17) . . ?
C16 C15 C14 121.0(2) . . ?
C17 C16 C15 119.7(2) . . ?
C16 C17 C18 121.75(19) . . ?
C17 C18 C13 118.10(18) . . ?
C17 C18 C19 119.08(18) . . ?
C13 C18 C19 122.81(17) . . ?
C20 C19 C18 111.46(18) . . ?
C20 C19 C21 110.03(19) . . ?
C18 C19 C21 111.92(18) . . ?
C14 C22 C24 114.33(17) . . ?
C14 C22 C23 109.58(18) . . ?
C24 C22 C23 110.17(18) . . ?
C27 C28 N1 120.4(2) . . ?
C28 C27 C26 117.9(3) . . ?
C25 C26 C27 112.2(3) . . ?
O1 C25 C26 119.3(3) . . ?

_diffrn_measured_fraction_theta_max 0.995
_diffrn_reflns_theta_full        25.03
_diffrn_measured_fraction_theta_full 0.995
_refine_diff_density_max         0.528
_refine_diff_density_min         -0.472
_refine_diff_density_rms         0.079