# Supplementary Material (ESI) for Chemical Communications # This journal is (c) The Royal Society of Chemistry 2009 data_global _journal_name_full Chem.Commun. _journal_coden_Cambridge 0182 _publ_contact_author_name 'Junliang Zhang' _publ_contact_author_email JLZHANG@CHEM.ECNU.EDU.CN _publ_section_title ; Tetrasubstituted Allenes by Pd0-Catalyzed Three-Component Tandem Michael Addition / Cross-Coupling Reaction ; loop_ _publ_author_name 'Junliang Zhang' 'Yuanjing Xiao' # Attachment '4aaa.cif' data_z _database_code_depnum_ccdc_archive 'CCDC 741112' #TrackingRef '4aaa.cif' _audit_creation_method SHELXL-97 _chemical_name_systematic ; ? ; _chemical_name_common ? _chemical_melting_point ? _chemical_formula_moiety ? _chemical_formula_sum 'C25 H22 O2' _chemical_formula_weight 354.43 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' _symmetry_cell_setting Orthorhombic _symmetry_space_group_name_H-M Pbca loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x+1/2, -y, z+1/2' '-x, y+1/2, -z+1/2' 'x+1/2, -y+1/2, -z' '-x, -y, -z' 'x-1/2, y, -z-1/2' 'x, -y-1/2, z-1/2' '-x-1/2, y-1/2, z' _cell_length_a 19.5589(7) _cell_length_b 8.1704(3) _cell_length_c 24.0587(9) _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 90.00 _cell_volume 3844.7(2) _cell_formula_units_Z 8 _cell_measurement_temperature 173(2) _cell_measurement_reflns_used ? _cell_measurement_theta_min ? _cell_measurement_theta_max ? _exptl_crystal_description block _exptl_crystal_colour colorless _exptl_crystal_size_max 0.452 _exptl_crystal_size_mid 0.368 _exptl_crystal_size_min 0.342 _exptl_crystal_density_meas ? _exptl_crystal_density_diffrn 1.225 _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 1504 _exptl_absorpt_coefficient_mu 0.076 _exptl_absorpt_correction_type multi-scan _exptl_absorpt_correction_T_min 0.780340 _exptl_absorpt_correction_T_max 1 _exptl_absorpt_process_details ? _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 ? _diffrn_measurement_method ? _diffrn_detector_area_resol_mean ? _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _diffrn_reflns_number 41565 _diffrn_reflns_av_R_equivalents 0.0295 _diffrn_reflns_av_sigmaI/netI 0.0135 _diffrn_reflns_limit_h_min -23 _diffrn_reflns_limit_h_max 23 _diffrn_reflns_limit_k_min -9 _diffrn_reflns_limit_k_max 9 _diffrn_reflns_limit_l_min -28 _diffrn_reflns_limit_l_max 28 _diffrn_reflns_theta_min 1.69 _diffrn_reflns_theta_max 25.01 _reflns_number_total 3388 _reflns_number_gt 3052 _reflns_threshold_expression >2sigma(I) _computing_data_collection ? _computing_cell_refinement ? _computing_data_reduction ? _computing_structure_solution 'SHELXS-97 (Sheldrick, 1990)' _computing_structure_refinement 'SHELXL-97 (Sheldrick, 1997)' _computing_molecular_graphics ? _computing_publication_material ? _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^)+(0.0421P)^2^+1.8562P] 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 none _refine_ls_extinction_coef ? _refine_ls_number_reflns 3388 _refine_ls_number_parameters 244 _refine_ls_number_restraints 0 _refine_ls_R_factor_all 0.0415 _refine_ls_R_factor_gt 0.0370 _refine_ls_wR_factor_ref 0.0973 _refine_ls_wR_factor_gt 0.0924 _refine_ls_goodness_of_fit_ref 1.054 _refine_ls_restrained_S_all 1.054 _refine_ls_shift/su_max 0.000 _refine_ls_shift/su_mean 0.000 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 O1 O 0.16466(6) 0.36263(14) -0.00992(5) 0.0467(3) Uani 1 1 d . . . O2 O 0.01482(5) 0.59326(12) 0.07550(4) 0.0289(2) Uani 1 1 d . . . C1 C 0.13139(7) 0.57238(17) 0.15836(6) 0.0298(3) Uani 1 1 d . . . H1A H 0.0969 0.5003 0.1715 0.036 Uiso 1 1 calc R . . C2 C 0.17806(8) 0.63834(19) 0.19530(6) 0.0359(3) Uani 1 1 d . . . H2A H 0.1754 0.6118 0.2337 0.043 Uiso 1 1 calc R . . C3 C 0.22872(7) 0.74299(19) 0.17648(7) 0.0389(4) Uani 1 1 d . . . H3A H 0.2608 0.7881 0.2019 0.047 Uiso 1 1 calc R . . C4 C 0.23242(7) 0.78141(19) 0.12079(7) 0.0388(4) Uani 1 1 d . . . H4A H 0.2671 0.8533 0.1078 0.047 Uiso 1 1 calc R . . C5 C 0.18571(7) 0.71536(17) 0.08373(6) 0.0315(3) Uani 1 1 d . . . H5A H 0.1887 0.7419 0.0454 0.038 Uiso 1 1 calc R . . C6 C 0.13478(6) 0.61107(16) 0.10212(6) 0.0257(3) Uani 1 1 d . . . C7 C 0.08246(7) 0.54259(16) 0.06167(6) 0.0265(3) Uani 1 1 d . . . H7A H 0.0936 0.5829 0.0235 0.032 Uiso 1 1 calc R . . C8 C 0.08284(6) 0.35664(16) 0.06117(5) 0.0244(3) Uani 1 1 d . . . C9 C 0.04495(6) 0.27227(16) 0.09601(5) 0.0249(3) Uani 1 1 d . . . C10 C 0.00580(6) 0.20445(16) 0.13391(5) 0.0243(3) Uani 1 1 d . . . C11 C 0.03650(7) 0.16090(16) 0.18892(5) 0.0246(3) Uani 1 1 d . . . C12 C 0.10069(7) 0.08889(18) 0.19251(6) 0.0330(3) Uani 1 1 d . . . H12A H 0.1248 0.0614 0.1595 0.040 Uiso 1 1 calc R . . C13 C 0.12976(8) 0.0569(2) 0.24385(7) 0.0396(4) Uani 1 1 d . . . H13A H 0.1739 0.0085 0.2458 0.047 Uiso 1 1 calc R . . C14 C 0.09523(8) 0.09459(19) 0.29198(6) 0.0389(4) Uani 1 1 d . . . H14A H 0.1153 0.0727 0.3271 0.047 Uiso 1 1 calc R . . C15 C 0.03097(8) 0.1647(2) 0.28876(6) 0.0380(4) Uani 1 1 d . . . H15A H 0.0068 0.1902 0.3219 0.046 Uiso 1 1 calc R . . C16 C 0.00172(7) 0.19782(18) 0.23774(6) 0.0313(3) Uani 1 1 d . . . H16A H -0.0424 0.2461 0.2360 0.038 Uiso 1 1 calc R . . C17 C -0.06869(7) 0.17833(16) 0.12424(5) 0.0246(3) Uani 1 1 d . . . C18 C -0.10293(7) 0.04708(17) 0.14871(6) 0.0293(3) Uani 1 1 d . . . H18A H -0.0785 -0.0275 0.1716 0.035 Uiso 1 1 calc R . . C19 C -0.17240(7) 0.02473(19) 0.13984(6) 0.0350(3) Uani 1 1 d . . . H19A H -0.1952 -0.0657 0.1564 0.042 Uiso 1 1 calc R . . C20 C -0.20862(7) 0.1336(2) 0.10702(6) 0.0358(3) Uani 1 1 d . . . H20A H -0.2562 0.1185 0.1011 0.043 Uiso 1 1 calc R . . C21 C -0.17501(7) 0.26452(19) 0.08286(6) 0.0332(3) Uani 1 1 d . . . H21A H -0.1997 0.3394 0.0603 0.040 Uiso 1 1 calc R . . C22 C -0.10569(7) 0.28712(17) 0.09137(5) 0.0285(3) Uani 1 1 d . . . H22A H -0.0831 0.3776 0.0747 0.034 Uiso 1 1 calc R . . C23 C 0.13058(7) 0.27825(17) 0.02088(6) 0.0288(3) Uani 1 1 d . . . C24 C 0.13681(8) 0.09599(18) 0.02047(6) 0.0364(3) Uani 1 1 d . . . H24A H 0.1699 0.0629 -0.0079 0.055 Uiso 1 1 calc R . . H24B H 0.0922 0.0473 0.0121 0.055 Uiso 1 1 calc R . . H24C H 0.1524 0.0582 0.0570 0.055 Uiso 1 1 calc R . . C25 C 0.00538(8) 0.76376(18) 0.06731(6) 0.0338(3) Uani 1 1 d . . . H25A H -0.0416 0.7937 0.0772 0.051 Uiso 1 1 calc R . . H25B H 0.0138 0.7909 0.0282 0.051 Uiso 1 1 calc R . . H25C H 0.0374 0.8245 0.0909 0.051 Uiso 1 1 calc R . . 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 O1 0.0527(7) 0.0390(6) 0.0485(7) 0.0055(5) 0.0279(6) -0.0004(5) O2 0.0251(5) 0.0284(5) 0.0333(5) 0.0006(4) -0.0001(4) 0.0020(4) C1 0.0275(7) 0.0299(7) 0.0320(7) 0.0003(6) 0.0024(6) 0.0005(6) C2 0.0361(8) 0.0385(8) 0.0331(8) -0.0026(7) -0.0037(6) 0.0047(6) C3 0.0293(7) 0.0371(8) 0.0502(9) -0.0100(7) -0.0084(7) 0.0020(6) C4 0.0263(7) 0.0338(8) 0.0563(10) -0.0026(7) 0.0033(7) -0.0054(6) C5 0.0300(7) 0.0278(7) 0.0368(8) 0.0020(6) 0.0058(6) 0.0005(6) C6 0.0233(6) 0.0228(6) 0.0308(7) -0.0006(6) 0.0022(5) 0.0040(5) C7 0.0265(7) 0.0276(7) 0.0254(7) 0.0022(6) 0.0035(5) 0.0005(5) C8 0.0256(6) 0.0263(7) 0.0214(6) 0.0014(5) -0.0010(5) -0.0022(5) C9 0.0247(6) 0.0265(7) 0.0236(6) -0.0018(5) -0.0020(5) 0.0018(5) C10 0.0262(6) 0.0228(6) 0.0238(6) -0.0009(5) 0.0031(5) 0.0007(5) C11 0.0263(6) 0.0226(6) 0.0250(7) 0.0013(5) 0.0018(5) -0.0044(5) C12 0.0306(7) 0.0378(8) 0.0305(7) 0.0012(6) 0.0029(6) 0.0028(6) C13 0.0351(8) 0.0423(9) 0.0414(9) 0.0056(7) -0.0069(6) 0.0025(7) C14 0.0461(9) 0.0409(8) 0.0297(8) 0.0072(7) -0.0090(7) -0.0120(7) C15 0.0434(8) 0.0457(9) 0.0248(7) -0.0029(7) 0.0033(6) -0.0119(7) C16 0.0295(7) 0.0351(8) 0.0293(8) -0.0022(6) 0.0043(6) -0.0034(6) C17 0.0268(7) 0.0257(7) 0.0212(6) -0.0037(5) 0.0030(5) 0.0003(5) C18 0.0311(7) 0.0282(7) 0.0286(7) 0.0010(6) 0.0002(6) -0.0008(6) C19 0.0327(7) 0.0369(8) 0.0354(8) -0.0017(6) 0.0035(6) -0.0090(6) C20 0.0266(7) 0.0451(9) 0.0358(8) -0.0085(7) -0.0016(6) -0.0008(6) C21 0.0330(7) 0.0365(8) 0.0300(7) -0.0033(6) -0.0039(6) 0.0071(6) C22 0.0333(7) 0.0287(7) 0.0234(6) -0.0004(6) 0.0016(5) 0.0016(6) C23 0.0288(7) 0.0317(7) 0.0258(7) 0.0014(6) 0.0025(6) -0.0005(6) C24 0.0420(8) 0.0327(8) 0.0345(8) -0.0018(6) 0.0067(6) 0.0042(6) C25 0.0359(8) 0.0300(7) 0.0356(8) 0.0003(6) -0.0053(6) 0.0067(6) _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 O1 C23 1.2119(17) . ? O2 C25 1.4190(17) . ? O2 C7 1.4257(15) . ? C1 C2 1.383(2) . ? C1 C6 1.3912(19) . ? C1 H1A 0.9500 . ? C2 C3 1.385(2) . ? C2 H2A 0.9500 . ? C3 C4 1.378(2) . ? C3 H3A 0.9500 . ? C4 C5 1.386(2) . ? C4 H4A 0.9500 . ? C5 C6 1.3834(19) . ? C5 H5A 0.9500 . ? C6 C7 1.5189(19) . ? C7 C8 1.5194(19) . ? C7 H7A 1.0000 . ? C8 C9 1.3142(19) . ? C8 C23 1.4906(18) . ? C9 C10 1.3132(18) . ? C10 C17 1.4908(18) . ? C10 C11 1.4964(18) . ? C11 C12 1.3892(19) . ? C11 C16 1.3904(19) . ? C12 C13 1.385(2) . ? C12 H12A 0.9500 . ? C13 C14 1.376(2) . ? C13 H13A 0.9500 . ? C14 C15 1.383(2) . ? C14 H14A 0.9500 . ? C15 C16 1.381(2) . ? C15 H15A 0.9500 . ? C16 H16A 0.9500 . ? C17 C22 1.3925(19) . ? C17 C18 1.3946(19) . ? C18 C19 1.387(2) . ? C18 H18A 0.9500 . ? C19 C20 1.384(2) . ? C19 H19A 0.9500 . ? C20 C21 1.384(2) . ? C20 H20A 0.9500 . ? C21 C22 1.384(2) . ? C21 H21A 0.9500 . ? C22 H22A 0.9500 . ? C23 C24 1.494(2) . ? C24 H24A 0.9800 . ? C24 H24B 0.9800 . ? C24 H24C 0.9800 . ? C25 H25A 0.9800 . ? C25 H25B 0.9800 . ? C25 H25C 0.9800 . ? 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 C25 O2 C7 111.92(10) . . ? C2 C1 C6 120.33(13) . . ? C2 C1 H1A 119.8 . . ? C6 C1 H1A 119.8 . . ? C1 C2 C3 120.17(14) . . ? C1 C2 H2A 119.9 . . ? C3 C2 H2A 119.9 . . ? C4 C3 C2 119.75(14) . . ? C4 C3 H3A 120.1 . . ? C2 C3 H3A 120.1 . . ? C3 C4 C5 120.14(14) . . ? C3 C4 H4A 119.9 . . ? C5 C4 H4A 119.9 . . ? C6 C5 C4 120.58(14) . . ? C6 C5 H5A 119.7 . . ? C4 C5 H5A 119.7 . . ? C5 C6 C1 119.03(13) . . ? C5 C6 C7 120.47(12) . . ? C1 C6 C7 120.49(12) . . ? O2 C7 C6 111.63(10) . . ? O2 C7 C8 107.26(10) . . ? C6 C7 C8 111.72(11) . . ? O2 C7 H7A 108.7 . . ? C6 C7 H7A 108.7 . . ? C8 C7 H7A 108.7 . . ? C9 C8 C23 122.87(12) . . ? C9 C8 C7 121.12(12) . . ? C23 C8 C7 115.96(11) . . ? C10 C9 C8 173.20(14) . . ? C9 C10 C17 121.46(12) . . ? C9 C10 C11 118.72(11) . . ? C17 C10 C11 119.74(11) . . ? C12 C11 C16 118.79(13) . . ? C12 C11 C10 121.21(12) . . ? C16 C11 C10 119.96(12) . . ? C13 C12 C11 120.43(14) . . ? C13 C12 H12A 119.8 . . ? C11 C12 H12A 119.8 . . ? C14 C13 C12 120.47(14) . . ? C14 C13 H13A 119.8 . . ? C12 C13 H13A 119.8 . . ? C13 C14 C15 119.44(14) . . ? C13 C14 H14A 120.3 . . ? C15 C14 H14A 120.3 . . ? C16 C15 C14 120.50(14) . . ? C16 C15 H15A 119.8 . . ? C14 C15 H15A 119.8 . . ? C15 C16 C11 120.37(14) . . ? C15 C16 H16A 119.8 . . ? C11 C16 H16A 119.8 . . ? C22 C17 C18 118.76(12) . . ? C22 C17 C10 120.33(12) . . ? C18 C17 C10 120.89(12) . . ? C19 C18 C17 120.42(13) . . ? C19 C18 H18A 119.8 . . ? C17 C18 H18A 119.8 . . ? C20 C19 C18 120.29(14) . . ? C20 C19 H19A 119.9 . . ? C18 C19 H19A 119.9 . . ? C21 C20 C19 119.55(13) . . ? C21 C20 H20A 120.2 . . ? C19 C20 H20A 120.2 . . ? C20 C21 C22 120.43(14) . . ? C20 C21 H21A 119.8 . . ? C22 C21 H21A 119.8 . . ? C21 C22 C17 120.54(13) . . ? C21 C22 H22A 119.7 . . ? C17 C22 H22A 119.7 . . ? O1 C23 C8 119.86(13) . . ? O1 C23 C24 121.21(13) . . ? C8 C23 C24 118.92(12) . . ? C23 C24 H24A 109.5 . . ? C23 C24 H24B 109.5 . . ? H24A C24 H24B 109.5 . . ? C23 C24 H24C 109.5 . . ? H24A C24 H24C 109.5 . . ? H24B C24 H24C 109.5 . . ? O2 C25 H25A 109.5 . . ? O2 C25 H25B 109.5 . . ? H25A C25 H25B 109.5 . . ? O2 C25 H25C 109.5 . . ? H25A C25 H25C 109.5 . . ? H25B C25 H25C 109.5 . . ? 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 _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion_publ_flag C6 C1 C2 C3 -0.3(2) . . . . ? C1 C2 C3 C4 0.1(2) . . . . ? C2 C3 C4 C5 -0.1(2) . . . . ? C3 C4 C5 C6 0.3(2) . . . . ? C4 C5 C6 C1 -0.5(2) . . . . ? C4 C5 C6 C7 178.30(13) . . . . ? C2 C1 C6 C5 0.4(2) . . . . ? C2 C1 C6 C7 -178.32(12) . . . . ? C25 O2 C7 C6 68.03(14) . . . . ? C25 O2 C7 C8 -169.27(11) . . . . ? C5 C6 C7 O2 -118.07(13) . . . . ? C1 C6 C7 O2 60.67(16) . . . . ? C5 C6 C7 C8 121.83(13) . . . . ? C1 C6 C7 C8 -59.43(16) . . . . ? O2 C7 C8 C9 -34.57(17) . . . . ? C6 C7 C8 C9 88.07(15) . . . . ? O2 C7 C8 C23 147.99(11) . . . . ? C6 C7 C8 C23 -89.37(14) . . . . ? C23 C8 C9 C10 166.1(11) . . . . ? C7 C8 C9 C10 -11.1(12) . . . . ? C8 C9 C10 C17 94.8(11) . . . . ? C8 C9 C10 C11 -82.0(11) . . . . ? C9 C10 C11 C12 -42.37(19) . . . . ? C17 C10 C11 C12 140.77(13) . . . . ? C9 C10 C11 C16 135.31(14) . . . . ? C17 C10 C11 C16 -41.54(18) . . . . ? C16 C11 C12 C13 -0.9(2) . . . . ? C10 C11 C12 C13 176.77(13) . . . . ? C11 C12 C13 C14 0.6(2) . . . . ? C12 C13 C14 C15 0.1(2) . . . . ? C13 C14 C15 C16 -0.5(2) . . . . ? C14 C15 C16 C11 0.1(2) . . . . ? C12 C11 C16 C15 0.6(2) . . . . ? C10 C11 C16 C15 -177.13(13) . . . . ? C9 C10 C17 C22 -32.01(19) . . . . ? C11 C10 C17 C22 144.76(13) . . . . ? C9 C10 C17 C18 149.32(13) . . . . ? C11 C10 C17 C18 -33.91(18) . . . . ? C22 C17 C18 C19 0.7(2) . . . . ? C10 C17 C18 C19 179.43(13) . . . . ? C17 C18 C19 C20 -0.7(2) . . . . ? C18 C19 C20 C21 0.3(2) . . . . ? C19 C20 C21 C22 -0.1(2) . . . . ? C20 C21 C22 C17 0.2(2) . . . . ? C18 C17 C22 C21 -0.5(2) . . . . ? C10 C17 C22 C21 -179.18(12) . . . . ? C9 C8 C23 O1 -179.37(14) . . . . ? C7 C8 C23 O1 -1.98(19) . . . . ? C9 C8 C23 C24 -1.1(2) . . . . ? C7 C8 C23 C24 176.32(12) . . . . ? _diffrn_measured_fraction_theta_max 1.000 _diffrn_reflns_theta_full 25.01 _diffrn_measured_fraction_theta_full 1.000 _refine_diff_density_max 0.307 _refine_diff_density_min -0.274 _refine_diff_density_rms 0.040