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The crystal structure of the gadolinium iron bis­muthide Gd6FeBi2 has been characterized by single-crystal X-ray diffraction data and analyzed in detail using first-principles calculations. The structure is isotypic with the Zr6CoAl2 structure, which is a variant of the ZrNiAl structure and its binary prototype Fe2P (Pearson code hP9, Wyckoff sequence g f d a). As such, the structure is best viewed as an array of tricapped trigonal prisms of Gd atoms centered alternately by Fe and Bi. The magnetic-ordering temperature of this compound (ca 350 K) is much higher than that of other rare-earth metal-rich phases with the same or related structures. It is also higher than the ordering temperature of many other Gd-rich ternary phases, where the magnetic exchange is typically governed by Ruderman–Kittel–Kasuya–Yosida (RKKY) inter­actions. First-principles calculations reveal a larger than expected Gd magnetic moment, with the additional contribution arising from the Gd 5d electrons. The electronic structure analysis suggests strong Gd 5d–Fe 3d hybridization to be the cause of this effect, rather than weak inter­actions between Gd and Bi. These details are of importance for understanding the magnetic response and explaining the high ordering tem­per­ature in this material.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S2053229619004868/fn3304sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S2053229619004868/fn3304Isup2.hkl
Contains datablock I

CCDC reference: 1909048

Computing details top

Data collection: SMART (Bruker, 2014); cell refinement: SMART (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL (Sheldrick, 2001); molecular graphics: CrystalMaker (CrystalMaker, 2007); software used to prepare material for publication: publCIF (Westrip, 2010).

Hexagadolinium iron bismuthide top
Crystal data top
Gd6FeBi2Dx = 9.246 Mg m3
Mr = 1417.31Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P62mCell parameters from 456 reflections
a = 8.337 (4) Åθ = 4.8–27.3°
c = 4.229 (2) ŵ = 74.21 mm1
V = 254.5 (2) Å3T = 150 K
Z = 1Irregular, grey-silver
F(000) = 5760.03 × 0.02 × 0.02 mm
Data collection top
Bruker SMART CCD area detector
diffractometer
297 independent reflections
Radiation source: fine-focus sealed tube285 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.076
phi and ω scansθmax = 29.5°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Bruker, 2014)
h = 1111
Tmin = 0.207, Tmax = 0.365k = 1011
2709 measured reflectionsl = 55
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.023 w = 1/[σ2(Fo2)]
wR(F2) = 0.040(Δ/σ)max < 0.001
S = 1.04Δρmax = 1.51 e Å3
297 reflectionsΔρmin = 1.71 e Å3
14 parametersAbsolute structure: (Flack, 1983)
0 restraintsAbsolute structure parameter: 0.014 (19)
Special details top

Geometry. 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.

Refinement. The data were collected on a Bruker SMART APEX CCD diffractometer using monochromated Mo Kα radiation (λ = 0.71073 Å). The SAINT software (Bruker, 2014) was used for the raw data reduction and integration. Semi-empirical absorption correction was applied with SADABS (Bruker, 2014). The crystal structure was solved by direct methods and refined by full-matrix least squares methods on F2 with SHELXL. The structure solution and refinement were straightforward. Direct methods provided the positions of all the atoms, and anisotropic refinement converged smoothly to low residuals and no unaccounted residual electron density. Trial refinements with freed occupations factors confirm that the structure is devoid of disorder.

Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Bi10.66670.33330.50000.0100 (2)
Gd10.76206 (13)0.00000.50000.0116 (2)
Gd20.40153 (15)0.00000.00000.0109 (2)
Fe10.00000.00000.00000.0156 (11)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Bi10.0095 (3)0.0095 (3)0.0108 (4)0.00476 (15)0.0000.000
Gd10.0095 (4)0.0081 (5)0.0166 (5)0.0041 (2)0.0000.000
Gd20.0116 (4)0.0109 (5)0.0099 (5)0.0055 (3)0.0000.000
Fe10.0195 (18)0.0195 (18)0.008 (2)0.0098 (9)0.0000.000
Geometric parameters (Å, º) top
Bi1—Gd13.2504 (17)Gd1—Gd2iv3.6749 (19)
Bi1—Gd1i3.2504 (17)Gd2—Bi1xiii3.3071 (12)
Bi1—Gd1ii3.2504 (17)Gd2—Bi1xiv3.3071 (12)
Bi1—Gd23.3071 (12)Gd2—Bi1viii3.3071 (12)
Bi1—Gd2iii3.3071 (12)Gd2—Fe13.347 (2)
Bi1—Gd2i3.3071 (12)Gd2—Gd1xv3.6015 (15)
Bi1—Gd2iv3.3071 (12)Gd2—Gd1ii3.6015 (15)
Bi1—Gd2v3.3071 (12)Gd2—Gd1xvi3.6015 (15)
Bi1—Gd2ii3.3071 (12)Gd2—Gd1xvii3.6015 (15)
Gd1—Fe1vi2.8993 (12)Gd2—Gd1xiii3.6749 (19)
Gd1—Fe1vii2.8993 (12)Fe1—Gd1ii2.8993 (12)
Gd1—Bi1viii3.2504 (17)Fe1—Gd1xv2.8993 (12)
Gd1—Gd1ix3.436 (2)Fe1—Gd1xviii2.8993 (12)
Gd1—Gd1x3.436 (2)Fe1—Gd1xvii2.8993 (12)
Gd1—Gd2iii3.6015 (15)Fe1—Gd1xix2.8993 (12)
Gd1—Gd2xi3.6015 (15)Fe1—Gd1xvi2.8993 (12)
Gd1—Gd2i3.6015 (15)Fe1—Gd2xx3.347 (2)
Gd1—Gd2xii3.6015 (15)Fe1—Gd2xxi3.347 (2)
Gd1—Gd23.6749 (19)
Gd1—Bi1—Gd1i120.0Gd2iii—Gd1—Gd2iv74.49 (2)
Gd1—Bi1—Gd1ii120.0Gd2xi—Gd1—Gd2iv114.09 (3)
Gd1i—Bi1—Gd1ii120.0Gd2i—Gd1—Gd2iv114.09 (3)
Gd1—Bi1—Gd268.16 (2)Gd2xii—Gd1—Gd2iv74.49 (2)
Gd1i—Bi1—Gd2140.24 (2)Gd2—Gd1—Gd2iv70.25 (5)
Gd1ii—Bi1—Gd266.62 (2)Bi1—Gd2—Bi1xiii79.49 (4)
Gd1—Bi1—Gd2iii66.62 (2)Bi1—Gd2—Bi1xiv151.25 (4)
Gd1i—Bi1—Gd2iii68.16 (2)Bi1xiii—Gd2—Bi1xiv93.39 (4)
Gd1ii—Bi1—Gd2iii140.24 (2)Bi1—Gd2—Bi1viii93.39 (4)
Gd2—Bi1—Gd2iii134.781 (13)Bi1xiii—Gd2—Bi1viii151.25 (4)
Gd1—Bi1—Gd2i66.62 (2)Bi1xiv—Gd2—Bi1viii79.49 (4)
Gd1i—Bi1—Gd2i68.16 (2)Bi1—Gd2—Fe1104.37 (2)
Gd1ii—Bi1—Gd2i140.24 (2)Bi1xiii—Gd2—Fe1104.37 (2)
Gd2—Bi1—Gd2i83.50 (3)Bi1xiv—Gd2—Fe1104.37 (2)
Gd2iii—Bi1—Gd2i79.49 (4)Bi1viii—Gd2—Fe1104.37 (2)
Gd1—Bi1—Gd2iv68.16 (2)Bi1—Gd2—Gd1xv152.23 (4)
Gd1i—Bi1—Gd2iv140.24 (2)Bi1xiii—Gd2—Gd1xv97.71 (4)
Gd1ii—Bi1—Gd2iv66.62 (2)Bi1xiv—Gd2—Gd1xv55.94 (2)
Gd2—Bi1—Gd2iv79.49 (4)Bi1viii—Gd2—Gd1xv100.99 (3)
Gd2iii—Bi1—Gd2iv83.50 (3)Fe1—Gd2—Gd1xv49.15 (2)
Gd2i—Bi1—Gd2iv134.781 (14)Bi1—Gd2—Gd1ii55.94 (2)
Gd1—Bi1—Gd2v140.24 (2)Bi1xiii—Gd2—Gd1ii100.99 (3)
Gd1i—Bi1—Gd2v66.62 (2)Bi1xiv—Gd2—Gd1ii152.23 (4)
Gd1ii—Bi1—Gd2v68.16 (2)Bi1viii—Gd2—Gd1ii97.71 (4)
Gd2—Bi1—Gd2v134.781 (14)Fe1—Gd2—Gd1ii49.15 (2)
Gd2iii—Bi1—Gd2v83.50 (3)Gd1xv—Gd2—Gd1ii98.30 (4)
Gd2i—Bi1—Gd2v134.781 (14)Bi1—Gd2—Gd1xvi97.71 (4)
Gd2iv—Bi1—Gd2v83.50 (3)Bi1xiii—Gd2—Gd1xvi152.23 (4)
Gd1—Bi1—Gd2ii140.24 (2)Bi1xiv—Gd2—Gd1xvi100.99 (3)
Gd1i—Bi1—Gd2ii66.62 (2)Bi1viii—Gd2—Gd1xvi55.94 (2)
Gd1ii—Bi1—Gd2ii68.16 (2)Fe1—Gd2—Gd1xvi49.15 (2)
Gd2—Bi1—Gd2ii83.50 (3)Gd1xv—Gd2—Gd1xvi71.90 (4)
Gd2iii—Bi1—Gd2ii134.781 (14)Gd1ii—Gd2—Gd1xvi56.98 (4)
Gd2i—Bi1—Gd2ii83.50 (3)Bi1—Gd2—Gd1xvii100.99 (3)
Gd2iv—Bi1—Gd2ii134.781 (14)Bi1xiii—Gd2—Gd1xvii55.93 (2)
Gd2v—Bi1—Gd2ii79.49 (4)Bi1xiv—Gd2—Gd1xvii97.71 (4)
Fe1vi—Gd1—Fe1vii93.66 (5)Bi1viii—Gd2—Gd1xvii152.23 (4)
Fe1vi—Gd1—Bi1viii117.379 (11)Fe1—Gd2—Gd1xvii49.15 (2)
Fe1vii—Gd1—Bi1viii117.379 (11)Gd1xv—Gd2—Gd1xvii56.98 (4)
Fe1vi—Gd1—Bi1117.379 (11)Gd1ii—Gd2—Gd1xvii71.90 (4)
Fe1vii—Gd1—Bi1117.379 (11)Gd1xvi—Gd2—Gd1xvii98.30 (4)
Bi1viii—Gd1—Bi195.53 (3)Bi1—Gd2—Gd155.19 (2)
Fe1vi—Gd1—Gd1ix53.663 (19)Bi1xiii—Gd2—Gd199.49 (4)
Fe1vii—Gd1—Gd1ix53.66 (2)Bi1xiv—Gd2—Gd199.49 (4)
Bi1viii—Gd1—Gd1ix162.232 (14)Bi1viii—Gd2—Gd155.19 (2)
Bi1—Gd1—Gd1ix102.233 (14)Fe1—Gd2—Gd1144.87 (2)
Fe1vi—Gd1—Gd1x53.66 (2)Gd1xv—Gd2—Gd1150.78 (2)
Fe1vii—Gd1—Gd1x53.663 (19)Gd1ii—Gd2—Gd1101.37 (4)
Bi1viii—Gd1—Gd1x102.233 (14)Gd1xvi—Gd2—Gd1101.37 (4)
Bi1—Gd1—Gd1x162.233 (14)Gd1xvii—Gd2—Gd1150.78 (2)
Gd1ix—Gd1—Gd1x60.0Bi1—Gd2—Gd1xiii99.49 (4)
Fe1vi—Gd1—Gd2iii60.85 (2)Bi1xiii—Gd2—Gd1xiii55.19 (2)
Fe1vii—Gd1—Gd2iii111.67 (3)Bi1xiv—Gd2—Gd1xiii55.19 (2)
Bi1viii—Gd1—Gd2iii130.83 (3)Bi1viii—Gd2—Gd1xiii99.49 (4)
Bi1—Gd1—Gd2iii57.443 (17)Fe1—Gd2—Gd1xiii144.87 (2)
Gd1ix—Gd1—Gd2iii61.511 (18)Gd1xv—Gd2—Gd1xiii101.37 (4)
Gd1x—Gd1—Gd2iii109.14 (2)Gd1ii—Gd2—Gd1xiii150.78 (2)
Fe1vi—Gd1—Gd2xi111.67 (3)Gd1xvi—Gd2—Gd1xiii150.78 (2)
Fe1vii—Gd1—Gd2xi60.85 (3)Gd1xvii—Gd2—Gd1xiii101.37 (4)
Bi1viii—Gd1—Gd2xi57.442 (17)Gd1—Gd2—Gd1xiii70.25 (5)
Bi1—Gd1—Gd2xi130.83 (3)Gd1ii—Fe1—Gd1xv139.991 (19)
Gd1ix—Gd1—Gd2xi109.14 (2)Gd1ii—Fe1—Gd1xviii139.991 (19)
Gd1x—Gd1—Gd2xi61.511 (18)Gd1xv—Fe1—Gd1xviii72.67 (4)
Gd2iii—Gd1—Gd2xi170.13 (4)Gd1ii—Fe1—Gd1xvii93.66 (5)
Fe1vi—Gd1—Gd2i111.67 (3)Gd1xv—Fe1—Gd1xvii72.67 (4)
Fe1vii—Gd1—Gd2i60.85 (3)Gd1xviii—Fe1—Gd1xvii72.67 (4)
Bi1viii—Gd1—Gd2i130.83 (3)Gd1ii—Fe1—Gd1xix72.67 (4)
Bi1—Gd1—Gd2i57.443 (17)Gd1xv—Fe1—Gd1xix139.991 (19)
Gd1ix—Gd1—Gd2i61.511 (18)Gd1xviii—Fe1—Gd1xix93.66 (5)
Gd1x—Gd1—Gd2i109.14 (2)Gd1xvii—Fe1—Gd1xix139.991 (19)
Gd2iii—Gd1—Gd2i71.90 (4)Gd1ii—Fe1—Gd1xvi72.67 (4)
Gd2xi—Gd1—Gd2i107.21 (4)Gd1xv—Fe1—Gd1xvi93.66 (5)
Fe1vi—Gd1—Gd2xii60.85 (3)Gd1xviii—Fe1—Gd1xvi139.991 (19)
Fe1vii—Gd1—Gd2xii111.67 (3)Gd1xvii—Fe1—Gd1xvi139.991 (19)
Bi1viii—Gd1—Gd2xii57.442 (17)Gd1xix—Fe1—Gd1xvi72.67 (4)
Bi1—Gd1—Gd2xii130.83 (3)Gd1ii—Fe1—Gd2xx133.17 (3)
Gd1ix—Gd1—Gd2xii109.14 (2)Gd1xv—Fe1—Gd2xx69.995 (10)
Gd1x—Gd1—Gd2xii61.511 (18)Gd1xviii—Fe1—Gd2xx69.995 (10)
Gd2iii—Gd1—Gd2xii107.21 (4)Gd1xvii—Fe1—Gd2xx133.17 (3)
Gd2xi—Gd1—Gd2xii71.90 (4)Gd1xix—Fe1—Gd2xx69.995 (10)
Gd2i—Gd1—Gd2xii170.13 (4)Gd1xvi—Fe1—Gd2xx69.995 (10)
Fe1vi—Gd1—Gd2168.30 (3)Gd1ii—Fe1—Gd2xxi69.995 (10)
Fe1vii—Gd1—Gd298.05 (4)Gd1xv—Fe1—Gd2xxi133.17 (3)
Bi1viii—Gd1—Gd256.651 (17)Gd1xviii—Fe1—Gd2xxi69.995 (10)
Bi1—Gd1—Gd256.651 (17)Gd1xvii—Fe1—Gd2xxi69.995 (10)
Gd1ix—Gd1—Gd2135.098 (17)Gd1xix—Fe1—Gd2xxi69.995 (10)
Gd1x—Gd1—Gd2135.098 (17)Gd1xvi—Fe1—Gd2xxi133.17 (3)
Gd2iii—Gd1—Gd2114.09 (3)Gd2xx—Fe1—Gd2xxi120.0
Gd2xi—Gd1—Gd274.49 (2)Gd1ii—Fe1—Gd269.995 (10)
Gd2i—Gd1—Gd274.49 (2)Gd1xv—Fe1—Gd269.995 (10)
Gd2xii—Gd1—Gd2114.09 (3)Gd1xviii—Fe1—Gd2133.17 (3)
Fe1vi—Gd1—Gd2iv98.05 (4)Gd1xvii—Fe1—Gd269.995 (10)
Fe1vii—Gd1—Gd2iv168.30 (3)Gd1xix—Fe1—Gd2133.17 (3)
Bi1viii—Gd1—Gd2iv56.651 (18)Gd1xvi—Fe1—Gd269.995 (10)
Bi1—Gd1—Gd2iv56.650 (17)Gd2xx—Fe1—Gd2120.0
Gd1ix—Gd1—Gd2iv135.098 (17)Gd2xxi—Fe1—Gd2120.0
Gd1x—Gd1—Gd2iv135.098 (17)
Symmetry codes: (i) y+1, xy, z; (ii) x+y+1, x+1, z; (iii) y+1, xy, z+1; (iv) x, y, z+1; (v) x+y+1, x+1, z+1; (vi) x+1, y, z+1; (vii) x+1, y, z; (viii) y, x1, z+1; (ix) x+y+2, x+1, z; (x) y+1, xy1, z; (xi) x+y+1, x, z; (xii) x+y+1, x, z+1; (xiii) x, y, z1; (xiv) y, x1, z; (xv) y, xy1, z1; (xvi) y, xy1, z; (xvii) x+y+1, x+1, z1; (xviii) x1, y, z1; (xix) x1, y, z; (xx) x+y, x, z; (xxi) y, xy, z.
Ordering temperature TC of selected Gd-rich compounds top
Chemical FormulaTC (K)Reference
Gd5Bi3110Szade & Drzyzga (2000)
Gd2In3187McAlister (1984)
Gd6CoTe2220Morozkin et al. (2010)
Gd4Sb3264Niu et al. (2001)
Gd4Sb1.5Bi1.5288Niu et al. (2001)
Gd4Bi3332Niu et al. (2001)
Gd (hcp)292Coey et al. (1999)
Gd6FeBi2350Zhang et al. (2016)
 

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