H3S (130 GPa) Structure: A3B_hR4_160_b_a

Picture of Structure; Click for Big Picture
Prototype : H3S
AFLOW prototype label : A3B_hR4_160_b_a
Strukturbericht designation : None
Pearson symbol : hR4
Space group number : 160
Space group symbol : $R3m$
AFLOW prototype command : aflow --proto=A3B_hR4_160_b_a [--hex]
--params=
$a$,$c/a$,$x_{1}$,$x_{2}$,$z_{2}$


  • This structure was found by first-principles electronic structure calculations and is predicted to be the stable structure of H3S 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 H3S Structure. The data presented here was computed at 130 GPa.

Rhombohedral primitive vectors:

\[ \begin{array}{ccc} \mathbf{a}_1 & = & ~ \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\ \mathbf{a}_2 & = & \frac{1}{\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\ \mathbf{a}_3 & = & - \frac12 \, a \, \mathbf{\hat{x}} - \frac{1}{2\sqrt{3}} \, a \, \mathbf{\hat{y}} + \frac13 \, c \, \mathbf{\hat{z}} \\ \end{array} \]

Basis vectors:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & = & x_{1} \, \mathbf{a}_{1} + x_{1} \, \mathbf{a}_{2} + x_{1} \, \mathbf{a}_{3} & = & x_{1}c \, \mathbf{\hat{z}} & \left(1a\right) & \mbox{S} \\ \mathbf{B}_{2} & = & x_{2} \, \mathbf{a}_{1} + x_{2} \, \mathbf{a}_{2} + z_{2} \, \mathbf{a}_{3} & = & \frac{1}{2}\left(x_{2}-z_{2}\right)a \, \mathbf{\hat{x}} + \frac{1}{2\sqrt{3}}\left(x_{2}-z_{2}\right)a \, \mathbf{\hat{y}} + \left(\frac{2}{3}x_{2}+\frac{1}{3}z_{2}\right)c \, \mathbf{\hat{z}} & \left(3b\right) & \mbox{H} \\ \mathbf{B}_{3} & = & z_{2} \, \mathbf{a}_{1} + x_{2} \, \mathbf{a}_{2} + x_{2} \, \mathbf{a}_{3} & = & \frac{1}{2}\left(-x_{2}+z_{2}\right)a \, \mathbf{\hat{x}} + \frac{1}{2\sqrt{3}}\left(x_{2}-z_{2}\right)a \, \mathbf{\hat{y}} + \left(\frac{2}{3}x_{2}+\frac{1}{3}z_{2}\right)c \, \mathbf{\hat{z}} & \left(3b\right) & \mbox{H} \\ \mathbf{B}_{4} & = & x_{2} \, \mathbf{a}_{1} + z_{2} \, \mathbf{a}_{2} + x_{2} \, \mathbf{a}_{3} & = & \frac{1}{\sqrt{3}}\left(-x_{2}+z_{2}\right)a \, \mathbf{\hat{y}} + \left(\frac{2}{3}x_{2}+\frac{1}{3}z_{2}\right)c \, \mathbf{\hat{z}} & \left(3b\right) & \mbox{H} \\ \end{array} \]

References

  • D. Duan, Y. Liu, F. Tian, D. Li, X. Huang, Z. Zhao, H. Yu, B. Liu, W. Tian, and T. Cui, Pressure–induced metallization of dense (H2S)2H2 with high–Tc superconductivity, Sci. Rep. 4, 6968 (2014), doi:10.1038/srep06968.

Geometry files


Prototype Generator

aflow --proto=A3B_hR4_160_b_a --params=

Species:

Running:

Output: