Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A3B_hR4_160_b_a-001

This structure originally had the label A3B_hR4_160_b_a. Calls to that address will be redirected here.

If you are using this page, please cite:
D. Hicks, M. J. Mehl, E. Gossett, C. Toher, O. Levy, R. M. Hanson, G. L. W. Hart, and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 2, Comp. Mat. Sci. 161, S1-S1011 (2019). (doi=10.1016/j.commatsci.2018.10.043)

Links to this page

https://aflow.org/p/P2LA
or https://aflow.org/p/A3B_hR4_160_b_a-001
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H$_{3}$S (130 GPa) Structure: A3B_hR4_160_b_a-001

Picture of Structure; Click for Big Picture
Prototype H$_{3}$S
AFLOW prototype label A3B_hR4_160_b_a-001
ICSD 291501
Pearson symbol hR4
Space group number 160
Space group symbol $R3m$
AFLOW prototype command aflow --proto=A3B_hR4_160_b_a-001
--params=$a, \allowbreak c/a, \allowbreak x_{1}, \allowbreak x_{2}, \allowbreak z_{2}$
View the structure from several different perspectives
View the primitive and conventional cell
  • This structure was found by first-principles electronic structure calculations and is predicted to be the stable structure of H$_{3}$S for pressures between 90 and 150 GPa. When $c/a \rightarrow \sqrt{8}$, $x_{2} \rightarrow 1/2$ and $z_{2} \rightarrow 0$ this structure continuously evolves into the cubic 200 GPa H$_{3}$S structure.
  • The data presented here was computed at 130 GPa.

Rhombohedral primitive vectors

\[ \begin{array}{ccc} \mathbf{a_{1}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{\sqrt{3}}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}- \frac{\sqrt{3}}{6}a \,\mathbf{\hat{y}}+\frac{1}{3}c \,\mathbf{\hat{z}} \end{array}\]
Picture of Structure; Click for Big Picture

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $x_{1} \, \mathbf{a}_{1}+x_{1} \, \mathbf{a}_{2}+x_{1} \, \mathbf{a}_{3}$ = $c x_{1} \,\mathbf{\hat{z}}$ (1a) S I
$\mathbf{B_{2}}$ = $x_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+z_{2} \, \mathbf{a}_{3}$ = $\frac{1}{2}a \left(x_{2} - z_{2}\right) \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \left(x_{2} - z_{2}\right) \,\mathbf{\hat{y}}+\frac{1}{3}c \left(2 x_{2} + z_{2}\right) \,\mathbf{\hat{z}}$ (3b) H I
$\mathbf{B_{3}}$ = $z_{2} \, \mathbf{a}_{1}+x_{2} \, \mathbf{a}_{2}+x_{2} \, \mathbf{a}_{3}$ = $- \frac{1}{2}a \left(x_{2} - z_{2}\right) \,\mathbf{\hat{x}}+\frac{\sqrt{3}}{6}a \left(x_{2} - z_{2}\right) \,\mathbf{\hat{y}}+\frac{1}{3}c \left(2 x_{2} + z_{2}\right) \,\mathbf{\hat{z}}$ (3b) H I
$\mathbf{B_{4}}$ = $x_{2} \, \mathbf{a}_{1}+z_{2} \, \mathbf{a}_{2}+x_{2} \, \mathbf{a}_{3}$ = $- \frac{1}{\sqrt{3}}a \left(x_{2} - z_{2}\right) \,\mathbf{\hat{y}}+\frac{1}{3}c \left(2 x_{2} + z_{2}\right) \,\mathbf{\hat{z}}$ (3b) H I

References

  • D. Duan, Y. Liu, F. T. D. Li, X. Huang, Z. Zhao, H. Yu, B. Liu, W. Tian, and T. Cui, Pressure-induced metallization of dense (H$_2$S)$_2$H$_2$ with high-T$_c$ superconductivity 4, 6968 (2014), doi:10.1038/srep06968.

Prototype Generator

aflow --proto=A3B_hR4_160_b_a --params=$a,c/a,x_{1},x_{2},z_{2}$

Species:

Running:

Output: