#------------------------------------------------------------------------------
#$Date: 2009-11-18 16:56:34 +0200 (Wed, 18 Nov 2009) $
#$Revision: 858 $
#$URL: svn://cod.ibt.lt/cod/cif/2/2003248.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_2003248
_journal_name_full               'Acta Crystallographica C'
_journal_volume                  51
_journal_year          1995
_journal_page_first    	346
_journal_page_last    	348
_publ_section_title
;
Strontium Diiron(III) Pyrophosphate
;
_chemical_formula_moiety    	'Fe2 O14 P4 Sr1'
_chemical_formula_sum            'Fe2 O14 P4 Sr'
_[local]_cod_chemical_formula_sum_orig 'Fe2 O14 P4 Sr1'
_chemical_formula_weight    	547.2
loop_
    _symmetry_equiv_pos_as_xyz
    x,y,z
    -x,-y,-z
_symmetry_space_group_name_H-M    	'P -1'
_cell_length_a    	4.795(1)
_cell_length_b    	7.108(1)
_cell_length_c    	7.830(2)
_cell_angle_alpha    	89.83(3)
_cell_angle_beta    	87.59(3)
_cell_angle_gamma    	73.11(3)
_cell_volume    	255.13(9)
_cell_formula_units_Z    	1
_exptl_crystal_density_diffrn    	3.561
_diffrn_radiation_type    	'Mo K\a'
_diffrn_radiation_wavelength    	0.71073
_cell_measurement_reflns_used    	45
_cell_measurement_theta_min    	10.0
_cell_measurement_theta_max    	17.0
_exptl_absorpt_coefficient_mu    	8.731
_cell_measurement_temperature    	298
_exptl_crystal_description    	'chunk'
_exptl_crystal_size_max    	0.3
_exptl_crystal_size_mid    	0.3
_exptl_crystal_size_min    	0.3
_exptl_crystal_colour    	'grey'
_chemical_compound_source
;
SrFe(III)₂(P₂O₇)₂ has been synthesized by
mixing stoichiometric amounta of (NH₄)₂HPO₄, SrCO₃ and
Fe₂O₃ according to the following equation:
SrCO₃ + 4(NH₄)₂HPO₄ + Fe₂O₃ => SrFe₂(P₂O₇)₂ +
8NH₃ + CO₂ + 6H₂O
After grinding, the mixture was heated progressively to 1243 K. The final
heating was followed by a return to room temperature in air.
Single crystals were prepared by grinding and heating an
appropriate mixture of material to 1275 K.
After 24 h at this temperature, the melt was cooled  (5 K h⁻¹)
allowing the isolation of grey crystals.
;
_diffrn_measurement_device    	'Syntex P4 4-circle'
_diffrn_measurement_method    	θ/2θ
_exptl_absorpt_correction_type    	'semi-empirical'
_exptl_absorpt_correction_T_min    	0.12
_exptl_absorpt_correction_T_max    	0.37
_diffrn_reflns_number    	1966
_reflns_number_total    	1483
_reflns_number_observed    	1247
_reflns_observed_criterion    	'F>4.0\s(F)'
_diffrn_reflns_av_R_equivalents    	0.0178
_diffrn_reflns_theta_max    	30
_diffrn_reflns_limit_h_min    	-1
_diffrn_reflns_limit_h_max    	6
_diffrn_reflns_limit_k_min    	-9
_diffrn_reflns_limit_k_max    	10
_diffrn_reflns_limit_l_min    	-11
_diffrn_reflns_limit_l_max    	11
_diffrn_standards_number    	3
_diffrn_standards_interval_count    	97
_diffrn_standards_decay_%    	0.0001
_refine_ls_structure_factor_coef    	F
_refine_ls_R_factor_obs    	.0378
_refine_ls_wR_factor_obs    	.0463
_refine_ls_goodness_of_fit_obs    	1.13
_refine_ls_number_reflns    	1247
_refine_ls_number_parameters    	101
_refine_ls_weighting_scheme    	'w = 1/[\s^2^(F)+ 0.0008F^2^]'
_refine_ls_shift/esd_max    	0.001
_refine_diff_density_max    	1.41
_refine_diff_density_min    	-0.85
loop_
    _atom_type_symbol
    _atom_type_scat_source
    _atom_type_scat_dispersion_real
    _atom_type_scat_dispersion_imag
    Fe 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 0.4 1.0
    Sr 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' -1.4 3.6
    P 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 0.1 0.2
    O 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 0.0 0.0
loop_
    _atom_site_label
    _atom_site_fract_x
    _atom_site_fract_y
    _atom_site_fract_z
    _atom_site_U_iso_or_equiv
    Sr1 0.500 0. 0. 0.027(1)
    Fe1 0.5000 0. 0.5000 0.017(1)
    Fe2 0. 0.5000 0. 0.018(1)
    P1 0.1184(2) -0.2307(2) 0.2988(1) 0.018(1)
    P2 0.5346(2) -0.6203(2) 0.2454(1) 0.017(1)
    O11 -0.1208(7) -0.1804(4) 0.4337(4) 0.022(1)
    O12 0.3199(7) -0.0993(4) 0.2933(4) 0.021(1)
    O13 0.0124(7) -0.2412(4) 0.1169(4) 0.020(1)
    O14 0.3104(7) -0.4469(4) 0.3504(4) 0.021(1)
    O21 0.8114(7) -0.5653(5) 0.2077(4) 0.022(1)
    O22 0.5887(7) -0.8062(4) 0.3457(4) 0.024(1)
    O23 0.3844(7) -0.6478(4) 0.0818(4) 0.020(1)
loop_
    _atom_site_aniso_label
    _atom_site_aniso_U_11
    _atom_site_aniso_U_12
    _atom_site_aniso_U_13
    _atom_site_aniso_U_22
    _atom_site_aniso_U_23
    _atom_site_aniso_U_33
    Sr1 0.034(1) -0.005(1) 0.000(1) 0.019(1) -0.001(1) 0.026(1)
    Fe1 0.018(1) -0.005(1) -0.001(1) 0.017(1) 0.000(1) 0.017(1)
    Fe2 0.017(1) -0.005(1) -0.002(1) 0.019(1) 0.000(1) 0.018(1)
    P1 0.017(1) -0.004(1) -0.001(1) 0.017(1) -0.002(1) 0.018(1)
    P2 0.017(1) -0.005(1) -0.002(1) 0.016(1) 0.000(1) 0.018(1)
    O11 0.019(1) -0.003(1) 0.000(1) 0.023(1) 0.000(1) 0.022(1)
    O12 0.022(1) -0.008(1) 0.000(1) 0.022(1) -0.004(1) 0.020(1)
    O13 0.020(1) -0.004(1) -0.004(1) 0.019(1) 0.000(1) 0.020(1)
    O14 0.019(1) -0.002(1) -0.001(1) 0.020(1) -0.001(1) 0.022(1)
    O21 0.021(1) -0.0011(1) -0.002(1) 0.027(1) 0.001(1) 0.021(1)
    O22 0.024(2) -0.004(1) 0.000(1) 0.018(1) 0.005(1) 0.027(1)
    O23 0.018(1) -0.004(1) -0.002(1) 0.021(1) -0.004(1) 0.021(1)
