Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A2BC4_tP7_111_e_b_n-001

This structure originally had the label A2BC4_tP7_111_f_a_n. Calls to that address will be redirected here.

If you are using this page, please cite:
D. Hicks, M.J. Mehl, M. Esters, C. Oses, O. Levy, G.L.W. Hart, C. Toher, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 3, Comp. Mat. Sci. 199, 110450 (2021). (doi=10.1016/j.commatsci.2021.110450)

Links to this page

https://aflow.org/p/34W5
or https://aflow.org/p/A2BC4_tP7_111_e_b_n-001
or PDF Version

$E3_{1}$ (β-Ag$_{2}$HgI$_{4}$) Structure: A2BC4_tP7_111_e_b_n-001

Picture of Structure; Click for Big Picture
Prototype Ag$_{2}$HgI$_{4}$
AFLOW prototype label A2BC4_tP7_111_e_b_n-001
Strukturbericht designation $E3_{1}$
ICSD 30264
Pearson symbol tP7
Space group number 111
Space group symbol $P\overline{4}2m$
AFLOW prototype command aflow --proto=A2BC4_tP7_111_e_b_n-001
--params=$a, \allowbreak c/a, \allowbreak x_{3}, \allowbreak z_{3}$

Other compounds with this structure

CdIn$_{2}$Se$_{4}$,  CuHg$_{2}$I$_{4}$


  • (Ketelaar, 1931) determined this pseudo-cubic structure for $\beta$–Ag$_{2}$HgI$_{4}$, and (Hermann, 1937) assigned it the Strukturbericht symbol $E3_{1}$. Later, (Browall, 1974) showed that $\beta$–Ag$_{2}$HgI$_{4}$ takes the Al$_{2}$CdS$_{4}$ structure, which (Pearson, 1967) listed as Strukturbericht $E3$.
  • The CdIn$_{2}$Se$_{4}$ structure found by (Hahn, 1955) does seem to be in this phase, so we have removed the obsolete label.

\[ \begin{array}{ccc} \mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}} \end{array}\]

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ (1b) Hg I
$\mathbf{B_{2}}$ = $\frac{1}{2} \, \mathbf{a}_{1}$ = $\frac{1}{2}a \,\mathbf{\hat{x}}$ (2e) Ag I
$\mathbf{B_{3}}$ = $\frac{1}{2} \, \mathbf{a}_{2}$ = $\frac{1}{2}a \,\mathbf{\hat{y}}$ (2e) Ag I
$\mathbf{B_{4}}$ = $x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ = $a x_{3} \,\mathbf{\hat{x}}+a x_{3} \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ (4n) I I
$\mathbf{B_{5}}$ = $- x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ = $- a x_{3} \,\mathbf{\hat{x}}- a x_{3} \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ (4n) I I
$\mathbf{B_{6}}$ = $x_{3} \, \mathbf{a}_{1}- x_{3} \, \mathbf{a}_{2}- z_{3} \, \mathbf{a}_{3}$ = $a x_{3} \,\mathbf{\hat{x}}- a x_{3} \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ (4n) I I
$\mathbf{B_{7}}$ = $- x_{3} \, \mathbf{a}_{1}+x_{3} \, \mathbf{a}_{2}- z_{3} \, \mathbf{a}_{3}$ = $- a x_{3} \,\mathbf{\hat{x}}+a x_{3} \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ (4n) I I

References

  • J. A. A. Ketelaar, Strukturbestimmung der komplexen Quecksilberverbindungen Ag$_{2}$HgJ$_{4}$ und Cu$_{2}$HgJ$_{4}$, Z. Krystallogr. 60, 190–203 (1931), doi:10.1524/zkri.1931.80.1.190.
  • C. Hermann, O. Lohrmann, and H. Philipp, eds., Strukturbericht Band II 1928-1932 (Akademische Verlagsgesellschaft M. B. H., Leipzig, 1937).
  • H. Hahn, G. Frank, W. Klingler, A. D. Störger, and G. Störger, Untersuchungen über ternäre Chalkogenide. VI. Über Ternäre Chalkogenide des Aluminiums, Galliums und Indiums mit Zink, Cadmium und Quecksilber, Z. Anorganische und Allgemeine Chemie 279, 241–270 (1955), doi:10.1002/zaac.19552790502.
  • W. B. Pearson, A Handbook of Lattice Spacings and Structures of Metals and Alloys, Volume 2, International Series of Monographs on Metal Physics and Physical Metallurgy, vol. 8 (Pergamon Press, Oxford, London, Edinburgh, New York, Toronto, Sydney, Paris, Braunschweig, 1967).

Found in

  • K. W. Browall, J. S. Kasper, and H. Wiedemeier, Single-crystal studies of $\beta$-Ag$_{2}$HgI$_{4}$, J. Solid State Chem. 10, 20–28 (1974), doi:10.1016/0022-4596(74)90004-8.

Prototype Generator

aflow --proto=A2BC4_tP7_111_e_b_n --params=$a,c/a,x_{3},z_{3}$

Species:

Running:

Output: