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Dimercury(II) germanium(IV) tetraselenide, Hg2GeSe4, adopts a cation-deficient diamond-like structure. It crystallizes in space group I\overline 4 of the tetragonal system. The structure consists of tetrahedral [HgSe4] and [GeSe4] groups. These groups are interconnected by sharing common corners. The previous structure report on Hg2GeSe4 based on powder diffraction data [Parasyuk et al., (2003). J. Alloys Compd, 351, 135-144] is comparable with our results except for the absolute configuration determination. In the asymmetric unit, the site symmetries of the Hg and Ge atoms are \overline 4.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536804034105/wm6045sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536804034105/wm6045Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 150 K
  • Mean [sigma](Se-Ge) = 0.003 Å
  • R factor = 0.056
  • wR factor = 0.145
  • Data-to-parameter ratio = 15.5

checkCIF/PLATON results

No syntax errors found



Alert level G REFLT03_ALERT_4_G WARNING: Large fraction of Friedel related reflns may be needed to determine absolute structure From the CIF: _diffrn_reflns_theta_max 27.42 From the CIF: _reflns_number_total 263 Count of symmetry unique reflns 222 Completeness (_total/calc) 118.47% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 41 Fraction of Friedel pairs measured 0.185 Are heavy atom types Z>Si present yes
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 0 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion

Computing details top

Data collection: MXC3 (MacScience, 1994); cell refinement: MXC3; data reduction: MXC3; program(s) used to solve structure: SHELXS86 (Sheldrick, 1985); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

(I) top
Crystal data top
Hg2GeSe4Dx = 7.241 Mg m3
Mr = 789.63Mo Kα radiation, λ = 0.7107 Å
Tetragonal, I4Cell parameters from 22 reflections
Hall symbol: I -4θ = 12.0–14.5°
a = 5.6741 (17) ŵ = 66.39 mm1
c = 11.249 (5) ÅT = 150 K
V = 362.2 (2) Å3Needle, black
Z = 20.40 × 0.02 × 0.01 mm
F(000) = 656
Data collection top
MacScience MXC3
diffractometer
Rint = 0.066
ω/2θ scansθmax = 27.4°, θmin = 3.6°
Absorption correction: analytical
(de Meulenaer & Tompa, 1965)
h = 07
Tmin = 0.220, Tmax = 0.520k = 07
288 measured reflectionsl = 014
263 independent reflections2 standard reflections every 100 reflections
260 reflections with I > 2σ(I) intensity decay: 0.5%
Refinement top
Refinement on F2 w = 1/[σ2(Fo2) + (0.12P)2 + 19.6039P]
where P = (Fo2 + 2Fc2)/3
Least-squares matrix: full(Δ/σ)max < 0.001
R[F2 > 2σ(F2)] = 0.056Δρmax = 3.24 e Å3
wR(F2) = 0.145Δρmin = 5.17 e Å3
S = 1.08Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
263 reflectionsExtinction coefficient: 0.027 (4)
17 parametersAbsolute structure: Flack (1983), 38 Friedel pairs
0 restraintsAbsolute structure parameter: 0.01 (6)
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Hg100.50.250.0109 (8)
Hg2000.50.0126 (8)
Ge00.50.750.0085 (16)
Se0.8068 (6)0.2374 (4)0.8823 (2)0.0072 (8)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Hg10.0109 (9)0.0109 (9)0.0109 (11)000
Hg20.0134 (9)0.0134 (9)0.0109 (11)000
Ge0.009 (2)0.009 (2)0.008 (3)000
Se0.0099 (14)0.0062 (15)0.0053 (12)0.0015 (12)0.0018 (11)0.0002 (11)
Geometric parameters (Å, º) top
Hg1—Sei2.658 (3)Ge—Seviii2.374 (2)
Hg1—Seii2.658 (3)Ge—Seix2.374 (2)
Hg1—Seiii2.658 (3)Ge—Sex2.374 (2)
Hg1—Seiv2.658 (3)Ge—Sev2.374 (2)
Hg2—Sev2.646 (3)Se—Gexi2.374 (2)
Hg2—Sevi2.646 (3)Se—Hg2xii2.646 (3)
Hg2—Seiii2.646 (3)Se—Hg1xiii2.658 (3)
Hg2—Sevii2.646 (3)
Sei—Hg1—Seii108.29 (5)Seiii—Hg2—Sevii119.97 (12)
Sei—Hg1—Seiii111.86 (11)Seviii—Ge—Seix102.34 (13)
Seii—Hg1—Seiii108.29 (5)Seviii—Ge—Sex113.15 (7)
Sei—Hg1—Seiv108.29 (5)Seix—Ge—Sex113.15 (7)
Seii—Hg1—Seiv111.86 (11)Seviii—Ge—Sev113.15 (7)
Seiii—Hg1—Seiv108.29 (5)Seix—Ge—Sev113.15 (7)
Sev—Hg2—Sevi119.97 (12)Sex—Ge—Sev102.34 (13)
Sev—Hg2—Seiii104.49 (5)Gexi—Se—Hg2xii105.31 (9)
Sevi—Hg2—Seiii104.49 (5)Gexi—Se—Hg1xiii105.62 (9)
Sev—Hg2—Sevii104.49 (5)Hg2xii—Se—Hg1xiii97.74 (12)
Sevi—Hg2—Sevii104.49 (5)
Symmetry codes: (i) x1/2, y+1/2, z1/2; (ii) y, x+1, z+1; (iii) x+1/2, y+1/2, z1/2; (iv) y, x, z+1; (v) y+1/2, x1/2, z+3/2; (vi) y1/2, x+1/2, z+3/2; (vii) x1/2, y1/2, z1/2; (viii) x+1, y+1, z; (ix) x1, y, z; (x) y1/2, x+3/2, z+3/2; (xi) x+1, y, z; (xii) x+1/2, y+1/2, z+1/2; (xiii) x+1/2, y1/2, z+1/2.
 

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