(IUCr) Hafnium germanium telluride

Volume 64
Part 5
Page i27
May 2008

Received 14 January 2008
Accepted 21 April 2008
Online 30 April 2008

Key indicators
Single-crystal X-ray study
T = 290 K
Mean (Hf-Ge) = 0.002 Å
R = 0.024
wR = 0.055
Data-to-parameter ratio = 23.9
Details

Hafnium germanium telluride

Gyung-Joo Jang ^a and Hoseop Yun ^a ^*

^aDivision of Energy Systems Research and Department of Chemistry, Ajou University, Suwon 443-749, Republic of Korea
Correspondence e-mail: hsyun@ajou.ac.kr

The title hafnium germanium telluride, HfGeTe₄, has been synthesized by the use of a halide flux and structurally characterized by X-ray diffraction. HfGeTe₄ is isostructural with stoichiometric ZrGeTe₄ and the Hf site in this compound is also fully occupied. The crystal structure of HfGeTe₄ adopts a two-dimensional layered structure, each layer being composed of two unique one-dimensional chains of face-sharing Hf-centered bicapped trigonal prisms and corner-sharing Ge-centered tetrahedra. These layers stack on top of each other to complete the three-dimensional structure with undulating van der Waals gaps.

Related literature

For the synthesis, crystal structure, and electronic structure of Hf_0.85GeTe₄, see: Mar & Ibers (1993). For the synthesis and structure of ZrGeTe₄, see: Lee et al. (2007). The title compound, HfGeTe₄, is isostructural with Hf_0.85GeTe₄ and ZrGeTe₄. However the Hf site in HfGeTe₄ is fully occupied. For related literature, see: Furuseth et al. (1973); Gelato & Parthé (1987); Smith & Bailey (1957); Zhao & Parthé (1990).

Experimental

Crystal data

HfGeTe₄
M_r = 761.48
Orthorhombic, C m c 2₁
a = 3.97951 (17) Å
b = 15.9530 (7) Å
c = 10.9731 (7) Å
V = 696.63 (6) Å³
Z = 4
Mo K radiation
= 35.50 mm^-1
T = 290 (1) K
0.30 × 0.02 × 0.02 mm

Data collection

Rigaku R-AXIS RAPID diffractometer
Absorption correction: numerical (NUMABS; Higashi, 2000) T_min = 0.425, T_max = 0.510
3348 measured reflections
910 independent reflections
878 reflections with I > 2(I)
R_int = 0.060

Refinement

R[F² > 2(F²)] = 0.023
wR(F²) = 0.054
S = 0.97
910 reflections
38 parameters
1 restraint
_max = 1.55 e Å^-3
_min = -2.00 e Å^-3
Absolute structure: Flack (1983), 431 Friedel pairs
Flack parameter: 0.008 (14)

Table 1
Selected geometric parameters (Å, °)

Hf-Geⁱ	2.8286 (15)
Hf-Te3ⁱⁱ	2.9454 (8)
Hf-Te3ⁱⁱⁱ	2.9454 (8)
Hf-Te1ⁱⁱⁱ	2.9524 (7)
Hf-Te1ⁱⁱ	2.9524 (7)
Hf-Te2ⁱⁱⁱ	2.9825 (8)
Hf-Te2ⁱⁱ	2.9825 (8)
Hf-Te4^iv	3.0312 (11)
Ge-Te4^v	2.6761 (10)
Ge-Te4^vi	2.6761 (10)
Ge-Te3	2.6955 (17)
Te1-Te2	2.7387 (13)

Te4^v-Ge-Te4^vi	96.07 (5)
Te4^v-Ge-Te3	92.35 (4)
Te4^v-Ge-Hf^iv	123.85 (4)
Te3-Ge-Hf^iv	120.07 (5)
Symmetry codes: (i) $[-x, -y+1, z-{\script{1\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ ; (iii) $[x-{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ ; (iv) $[-x, -y+1, z+{\script{1\over 2}}]$ ; (v) $[-x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (vi) $[-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: RAPID-AUTO (Rigaku, 2006); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: locally modified version of ORTEP (Johnson, 1965); software used to prepare material for publication: WinGX (Farrugia, 1999).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GW2040 ).

Acknowledgements

This research was supported by the Korean Research Foundation (KRF-2006-521-C00088). Use was made of the X-ray facilities supported by Ajou University.

References

Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.
Flack, H. D. (1983). Acta Cryst. A39, 876-881.
Furuseth, S., Brattås, L. & Kjekshus, A. (1973). Acta Chem. Scand. 27, 2367-2374.
Gelato, L. M. & Parthé, E. (1987). J. Appl. Cryst. 20, 139-143.
Higashi, T. (2000). NUMABS. Rigaku Corporation, Tokyo, Japan.
Johnson, C. K. (1965). ORTEP. Report ORNL-3794. Oak Ridge National Laboratory, Tennessee, USA.
Lee, C.-H., Jang, G.-J. & Yun, H. (2007). Acta Cryst. E63, i183.
Mar, A. & Ibers, J. (1993). J. Am. Chem. Soc. 115, 3227-3238.
Rigaku (2006). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Smith, J. F. & Bailey, D. M. (1957). Acta Cryst. 10, 341-342.
Zhao, J.-T. & Parthé, E. (1990). J. Less-Common Met. 162, 27-29.

inorganic compounds