Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807050568/wm2152sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807050568/wm2152Isup2.hkl |
The sample with composition Ni56.5Te43.5 was prepared by fusion of the elemental constituents (Alfa Aesar, > 99.9 wt. %) in an evacuated silica ampoule. The synthesis was performed in a tube furnace with a heating rate of 30 K/h and a maximum temperature of about 1370 K. The sample was kept at this temperature for 4 h. Afterwards it was cooled slowly down to 850 K with a rate of 10 K/h and annealed at 850 K for another 240 h. Then the sample was quenched in cold water. The obtained black crystals had a prismatic habit and maximal lengths of 0.2 mm.
The site occupancy factors for Ni2 and Ni3 were constrained (s.o.f. = 0.8) according to the employed composition of the sample. Results of single-crystal reinvestigation of Ni2.60Te2 agree well with those reported on the basis of the powder diffraction study, but with improved precision on atomic coordinates and interatomic distances. Space group Pnma was confirmed with PLATON (Spek, 2003) and no additional symmetry elements were found. The highest peak and the deepest hole in the final Fourier map are found 1.78 Å and 1.05 Å, respectively, from atom Te1.
The crystal structure of the binary Ni2.58Te2 compound has been investigated recently using X-ray powder diffraction data (space group Pmc21, a = 3.9089 (2) Å, b = 6.8627 (3) Å, c = 12.3400 (6) Å; Gulay & Olekseyuk, 2004). We have now redetermined the crystal structure of this compound by means of single-crystal X-ray diffraction data and present the results here.
The composition Ni2.60Te2 and the unit-cell parameters of the single-crystal study are very similar to those of the powder refinement. However, the centrosymmetric space group Pnma was determined for the title compound in contrast to the non-centrosymmetric space group Pmc21 determined for the powder study. Nevertheless, the topologies and interatomic distances of both centrosymmetric and non-centrosymmetric models are very similar. The structure can be described as a close-packed arrangement of Te atoms with a stacking sequence of the layers as –ABAC–. The Ni atoms partially occupy octahedral and tetrahedral interstices of the Te sublattice. The unit cell and coordination polyhedra of the Ni atoms are shown in Fig. 1. In an alternative description, the structure of the compound can be viewed as a c× a × (3a)1/2 distorted orthorhombic variant of the hexagonal Ni1.10Se0.16Te0.74 structure (space group P63/mmc, a = 3.836 (1) Å, c = 12.24 (1) Å; Haugsten & Røst, 1972).
For the previous structure refinement of the title compound from powder data, see: Gulay & Olekseyuk (2004). For the Ni1.10Se0.16Te0.74 structure, see: Haugsten & Røst (1972). For crystallographic tools, see: Spek (2003).
Data collection: CrysAlis CCD (Oxford Diffraction, 2007); cell refinement: CrysAlis RED (Oxford Diffraction, 2007); data reduction: CrysAlis RED (Oxford Diffraction, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2005); software used to prepare material for publication: publCIF (Westrip, 2007).
Fig. 1. The crystal structure of Ni2.60Te2 viewed along the b axis and displayed with displacement ellipsoids at the 50% probability level. |
Ni2.60Te2 | F(000) = 707 |
Mr = 407.85 | Dx = 8.113 Mg m−3 |
Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 329 reflections |
a = 12.380 (2) Å | θ = 3.4–25.0° |
b = 3.9192 (8) Å | µ = 31.39 mm−1 |
c = 6.8818 (13) Å | T = 293 K |
V = 333.91 (12) Å3 | Prism, black |
Z = 4 | 0.14 × 0.09 × 0.04 mm |
Kuma KM-4 with CCD area-detector diffractometer | 335 independent reflections |
Radiation source: fine-focus sealed tube | 329 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.068 |
Detector resolution: 1024x1024 with blocks 2x2, 33.133pixel/mm pixels mm-1 | θmax = 25.0°, θmin = 3.4° |
ω scans | h = −14→12 |
Absorption correction: numerical CrysAlis RED (Oxford Diffraction, 2007) | k = −4→4 |
Tmin = 0.051, Tmax = 0.323 | l = −8→8 |
2788 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.025 | w = 1/[σ2(Fo2) + (0.0225P)2 + 4.6665P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.060 | (Δ/σ)max < 0.001 |
S = 1.10 | Δρmax = 1.23 e Å−3 |
335 reflections | Δρmin = −1.45 e Å−3 |
32 parameters | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0020 (3) |
Ni2.60Te2 | V = 333.91 (12) Å3 |
Mr = 407.85 | Z = 4 |
Orthorhombic, Pnma | Mo Kα radiation |
a = 12.380 (2) Å | µ = 31.39 mm−1 |
b = 3.9192 (8) Å | T = 293 K |
c = 6.8818 (13) Å | 0.14 × 0.09 × 0.04 mm |
Kuma KM-4 with CCD area-detector diffractometer | 335 independent reflections |
Absorption correction: numerical CrysAlis RED (Oxford Diffraction, 2007) | 329 reflections with I > 2σ(I) |
Tmin = 0.051, Tmax = 0.323 | Rint = 0.068 |
2788 measured reflections |
R[F2 > 2σ(F2)] = 0.025 | 32 parameters |
wR(F2) = 0.060 | 0 restraints |
S = 1.10 | Δρmax = 1.23 e Å−3 |
335 reflections | Δρmin = −1.45 e Å−3 |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. 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 > σ(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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Ni1 | 0.05235 (10) | 0.2500 | 0.4203 (2) | 0.0152 (4) | |
Ni2 | 0.14310 (14) | 0.2500 | 0.0802 (3) | 0.0185 (4) | 0.80 |
Ni3 | 0.15349 (14) | −0.2500 | 0.5956 (3) | 0.0191 (5) | 0.80 |
Te1 | 0.25343 (5) | 0.2500 | 0.42149 (10) | 0.0131 (3) | |
Te2 | 0.00373 (5) | 0.2500 | 0.78163 (10) | 0.0146 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ni1 | 0.0131 (7) | 0.0139 (7) | 0.0186 (8) | 0.000 | 0.0020 (6) | 0.000 |
Ni2 | 0.0139 (9) | 0.0235 (9) | 0.0182 (10) | 0.000 | 0.0043 (7) | 0.000 |
Ni3 | 0.0109 (9) | 0.0182 (9) | 0.0283 (11) | 0.000 | −0.0046 (8) | 0.000 |
Te1 | 0.0095 (4) | 0.0123 (4) | 0.0174 (5) | 0.000 | −0.0001 (2) | 0.000 |
Te2 | 0.0159 (5) | 0.0117 (4) | 0.0162 (4) | 0.000 | −0.0007 (3) | 0.000 |
Ni1—Te1 | 2.4894 (14) | Ni2—Te2vi | 2.6831 (19) |
Ni1—Te2i | 2.5007 (10) | Ni2—Te1 | 2.717 (2) |
Ni1—Te2ii | 2.5007 (10) | Ni2—Te2i | 2.8370 (13) |
Ni1—Ni3i | 2.551 (2) | Ni2—Te2ii | 2.8370 (13) |
Ni1—Te2 | 2.5582 (16) | Ni3—Ni2vii | 2.521 (3) |
Ni1—Ni1i | 2.5928 (16) | Ni3—Te1vii | 2.5214 (19) |
Ni1—Ni1ii | 2.5928 (16) | Ni3—Ni1i | 2.551 (2) |
Ni1—Ni2 | 2.596 (2) | Ni3—Te1 | 2.6090 (13) |
Ni1—Ni3iii | 2.6197 (14) | Ni3—Te1viii | 2.6090 (13) |
Ni1—Ni3 | 2.6197 (14) | Ni3—Ni1viii | 2.6197 (14) |
Ni2—Ni3iv | 2.521 (3) | Ni3—Te2viii | 2.9860 (15) |
Ni2—Te1v | 2.5834 (12) | Ni3—Te2 | 2.9860 (15) |
Ni2—Te1iv | 2.5834 (12) | ||
Te1—Ni1—Te2i | 106.22 (4) | Ni2vii—Ni3—Te1viii | 60.45 (4) |
Te1—Ni1—Te2ii | 106.22 (4) | Te1vii—Ni3—Te1viii | 101.05 (5) |
Te2i—Ni1—Te2ii | 103.18 (6) | Ni1i—Ni3—Te1viii | 117.01 (5) |
Te1—Ni1—Ni3i | 177.72 (8) | Te1—Ni3—Te1viii | 97.37 (6) |
Te2i—Ni1—Ni3i | 72.47 (4) | Ni2vii—Ni3—Ni1viii | 117.27 (6) |
Te2ii—Ni1—Ni3i | 72.47 (4) | Te1vii—Ni3—Ni1viii | 128.90 (4) |
Te1—Ni1—Te2 | 103.43 (5) | Ni1i—Ni3—Ni1viii | 60.18 (5) |
Te2i—Ni1—Te2 | 118.35 (4) | Te1—Ni3—Ni1viii | 125.24 (7) |
Te2ii—Ni1—Te2 | 118.35 (4) | Te1viii—Ni3—Ni1viii | 56.86 (3) |
Ni3i—Ni1—Te2 | 78.85 (6) | Ni2vii—Ni3—Ni1 | 117.27 (6) |
Te1—Ni1—Ni1i | 119.91 (6) | Te1vii—Ni3—Ni1 | 128.90 (4) |
Te2i—Ni1—Ni1i | 60.26 (4) | Ni1i—Ni3—Ni1 | 60.18 (5) |
Te2ii—Ni1—Ni1i | 133.51 (8) | Te1—Ni3—Ni1 | 56.86 (3) |
Ni3i—Ni1—Ni1i | 61.23 (5) | Te1viii—Ni3—Ni1 | 125.24 (7) |
Te2—Ni1—Ni1i | 58.08 (5) | Ni1viii—Ni3—Ni1 | 96.84 (7) |
Te1—Ni1—Ni1ii | 119.91 (6) | Ni2vii—Ni3—Te2viii | 129.67 (5) |
Te2i—Ni1—Ni1ii | 133.51 (8) | Te1vii—Ni3—Te2viii | 84.40 (5) |
Te2ii—Ni1—Ni1ii | 60.26 (4) | Ni1i—Ni3—Te2viii | 52.99 (4) |
Ni3i—Ni1—Ni1ii | 61.23 (5) | Te1—Ni3—Te2viii | 169.83 (6) |
Te2—Ni1—Ni1ii | 58.08 (5) | Te1viii—Ni3—Te2viii | 89.91 (2) |
Ni1i—Ni1—Ni1ii | 98.19 (8) | Ni1viii—Ni3—Te2viii | 53.82 (4) |
Te1—Ni1—Ni2 | 64.54 (5) | Ni1—Ni3—Te2viii | 113.05 (6) |
Te2i—Ni1—Ni2 | 67.61 (4) | Ni2vii—Ni3—Te2 | 129.67 (5) |
Te2ii—Ni1—Ni2 | 67.61 (4) | Te1vii—Ni3—Te2 | 84.40 (5) |
Ni3i—Ni1—Ni2 | 113.18 (8) | Ni1i—Ni3—Te2 | 52.99 (4) |
Te2—Ni1—Ni2 | 167.97 (7) | Te1—Ni3—Te2 | 89.91 (2) |
Ni1i—Ni1—Ni2 | 126.70 (6) | Te1viii—Ni3—Te2 | 169.83 (6) |
Ni1ii—Ni1—Ni2 | 126.70 (6) | Ni1viii—Ni3—Te2 | 113.05 (6) |
Te1—Ni1—Ni3iii | 61.35 (4) | Ni1—Ni3—Te2 | 53.82 (4) |
Te2i—Ni1—Ni3iii | 167.10 (6) | Te2viii—Ni3—Te2 | 82.03 (5) |
Te2ii—Ni1—Ni3iii | 78.60 (4) | Ni1—Te1—Ni3iv | 117.01 (6) |
Ni3i—Ni1—Ni3iii | 119.82 (5) | Ni1—Te1—Ni2ix | 119.82 (4) |
Te2—Ni1—Ni3iii | 70.43 (5) | Ni3iv—Te1—Ni2ix | 98.59 (5) |
Ni1i—Ni1—Ni3iii | 127.56 (9) | Ni1—Te1—Ni2vii | 119.82 (4) |
Ni1ii—Ni1—Ni3iii | 58.59 (5) | Ni3iv—Te1—Ni2vii | 98.59 (5) |
Ni2—Ni1—Ni3iii | 102.02 (6) | Ni2ix—Te1—Ni2vii | 98.67 (6) |
Te1—Ni1—Ni3 | 61.35 (4) | Ni1—Te1—Ni3iii | 61.78 (4) |
Te2i—Ni1—Ni3 | 78.60 (4) | Ni3iv—Te1—Ni3iii | 128.70 (4) |
Te2ii—Ni1—Ni3 | 167.10 (6) | Ni2ix—Te1—Ni3iii | 58.08 (6) |
Ni3i—Ni1—Ni3 | 119.82 (5) | Ni2vii—Te1—Ni3iii | 127.64 (6) |
Te2—Ni1—Ni3 | 70.43 (5) | Ni1—Te1—Ni3 | 61.78 (4) |
Ni1i—Ni1—Ni3 | 58.59 (5) | Ni3iv—Te1—Ni3 | 128.70 (4) |
Ni1ii—Ni1—Ni3 | 127.56 (9) | Ni2ix—Te1—Ni3 | 127.64 (6) |
Ni2—Ni1—Ni3 | 102.02 (6) | Ni2vii—Te1—Ni3 | 58.08 (6) |
Ni3iii—Ni1—Ni3 | 96.84 (7) | Ni3iii—Te1—Ni3 | 97.37 (6) |
Ni3iv—Ni2—Te1v | 61.47 (4) | Ni1—Te1—Ni2 | 59.64 (5) |
Ni3iv—Ni2—Te1iv | 61.47 (4) | Ni3iv—Te1—Ni2 | 57.38 (6) |
Te1v—Ni2—Te1iv | 98.67 (6) | Ni2ix—Te1—Ni2 | 127.93 (4) |
Ni3iv—Ni2—Ni1 | 113.23 (8) | Ni2vii—Te1—Ni2 | 127.93 (4) |
Te1v—Ni2—Ni1 | 126.56 (4) | Ni3iii—Te1—Ni2 | 99.12 (5) |
Te1iv—Ni2—Ni1 | 126.56 (4) | Ni3—Te1—Ni2 | 99.12 (5) |
Ni3iv—Ni2—Te2vi | 132.43 (8) | Ni1i—Te2—Ni1ii | 103.18 (6) |
Te1v—Ni2—Te2vi | 89.72 (5) | Ni1i—Te2—Ni1 | 61.65 (4) |
Te1iv—Ni2—Te2vi | 89.72 (5) | Ni1ii—Te2—Ni1 | 61.65 (4) |
Ni1—Ni2—Te2vi | 114.34 (7) | Ni1i—Te2—Ni2x | 127.17 (3) |
Ni3iv—Ni2—Te1 | 57.41 (6) | Ni1ii—Te2—Ni2x | 127.17 (3) |
Te1v—Ni2—Te1 | 96.67 (5) | Ni1—Te2—Ni2x | 126.37 (5) |
Te1iv—Ni2—Te1 | 96.67 (5) | Ni1i—Te2—Ni2i | 57.80 (4) |
Ni1—Ni2—Te1 | 55.82 (5) | Ni1ii—Te2—Ni2i | 123.34 (5) |
Te2vi—Ni2—Te1 | 170.16 (8) | Ni1—Te2—Ni2i | 118.46 (4) |
Ni3iv—Ni2—Te2i | 128.76 (5) | Ni2x—Te2—Ni2i | 98.94 (5) |
Te1v—Ni2—Te2i | 169.54 (7) | Ni1i—Te2—Ni2ii | 123.34 (5) |
Te1iv—Ni2—Te2i | 86.30 (2) | Ni1ii—Te2—Ni2ii | 57.80 (4) |
Ni1—Ni2—Te2i | 54.59 (3) | Ni1—Te2—Ni2ii | 118.46 (4) |
Te2vi—Ni2—Te2i | 81.06 (5) | Ni2x—Te2—Ni2ii | 98.94 (5) |
Te1—Ni2—Te2i | 91.86 (5) | Ni2i—Te2—Ni2ii | 87.38 (5) |
Ni3iv—Ni2—Te2ii | 128.76 (5) | Ni1i—Te2—Ni3iii | 116.64 (5) |
Te1v—Ni2—Te2ii | 86.30 (2) | Ni1ii—Te2—Ni3iii | 54.54 (4) |
Te1iv—Ni2—Te2ii | 169.54 (7) | Ni1—Te2—Ni3iii | 55.75 (4) |
Ni1—Ni2—Te2ii | 54.59 (3) | Ni2x—Te2—Ni3iii | 85.93 (5) |
Te2vi—Ni2—Te2ii | 81.06 (5) | Ni2i—Te2—Ni3iii | 174.17 (5) |
Te1—Ni2—Te2ii | 91.86 (5) | Ni2ii—Te2—Ni3iii | 95.06 (4) |
Te2i—Ni2—Te2ii | 87.38 (5) | Ni1i—Te2—Ni3 | 54.54 (4) |
Ni2vii—Ni3—Te1vii | 65.21 (6) | Ni1ii—Te2—Ni3 | 116.64 (5) |
Ni2vii—Ni3—Ni1i | 175.12 (10) | Ni1—Te2—Ni3 | 55.75 (4) |
Te1vii—Ni3—Ni1i | 119.66 (8) | Ni2x—Te2—Ni3 | 85.93 (5) |
Ni2vii—Ni3—Te1 | 60.45 (4) | Ni2i—Te2—Ni3 | 95.06 (4) |
Te1vii—Ni3—Te1 | 101.05 (5) | Ni2ii—Te2—Ni3 | 174.17 (5) |
Ni1i—Ni3—Te1 | 117.01 (5) | Ni3iii—Te2—Ni3 | 82.03 (5) |
Symmetry codes: (i) −x, −y, −z+1; (ii) −x, −y+1, −z+1; (iii) x, y+1, z; (iv) −x+1/2, −y, z−1/2; (v) −x+1/2, −y+1, z−1/2; (vi) x, y, z−1; (vii) −x+1/2, −y, z+1/2; (viii) x, y−1, z; (ix) −x+1/2, −y+1, z+1/2; (x) x, y, z+1. |
Experimental details
Crystal data | |
Chemical formula | Ni2.60Te2 |
Mr | 407.85 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 293 |
a, b, c (Å) | 12.380 (2), 3.9192 (8), 6.8818 (13) |
V (Å3) | 333.91 (12) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 31.39 |
Crystal size (mm) | 0.14 × 0.09 × 0.04 |
Data collection | |
Diffractometer | Kuma KM-4 with CCD area-detector |
Absorption correction | Numerical CrysAlis RED (Oxford Diffraction, 2007) |
Tmin, Tmax | 0.051, 0.323 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2788, 335, 329 |
Rint | 0.068 |
(sin θ/λ)max (Å−1) | 0.594 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.025, 0.060, 1.10 |
No. of reflections | 335 |
No. of parameters | 32 |
Δρmax, Δρmin (e Å−3) | 1.23, −1.45 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2007), CrysAlis RED (Oxford Diffraction, 2007), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 2005), publCIF (Westrip, 2007).
The crystal structure of the binary Ni2.58Te2 compound has been investigated recently using X-ray powder diffraction data (space group Pmc21, a = 3.9089 (2) Å, b = 6.8627 (3) Å, c = 12.3400 (6) Å; Gulay & Olekseyuk, 2004). We have now redetermined the crystal structure of this compound by means of single-crystal X-ray diffraction data and present the results here.
The composition Ni2.60Te2 and the unit-cell parameters of the single-crystal study are very similar to those of the powder refinement. However, the centrosymmetric space group Pnma was determined for the title compound in contrast to the non-centrosymmetric space group Pmc21 determined for the powder study. Nevertheless, the topologies and interatomic distances of both centrosymmetric and non-centrosymmetric models are very similar. The structure can be described as a close-packed arrangement of Te atoms with a stacking sequence of the layers as –ABAC–. The Ni atoms partially occupy octahedral and tetrahedral interstices of the Te sublattice. The unit cell and coordination polyhedra of the Ni atoms are shown in Fig. 1. In an alternative description, the structure of the compound can be viewed as a c× a × (3a)1/2 distorted orthorhombic variant of the hexagonal Ni1.10Se0.16Te0.74 structure (space group P63/mmc, a = 3.836 (1) Å, c = 12.24 (1) Å; Haugsten & Røst, 1972).