CaC6 Structure: A6B_hR7_166_g_a

Picture of Structure; Click for Big Picture
Prototype : CaC6
AFLOW prototype label : A6B_hR7_166_g_a
Strukturbericht designation : None
Pearson symbol : hR7
Space group number : 166
Space group symbol : $\mbox{R}\bar{3}\mbox{m}$
AFLOW prototype command : aflow --proto=A6B_hR7_166_g_a [--hex]
--params=
$a$,$c/a$,$x_{2}$


  • Superconducting structure, T$_{c}$ = 11.5K. Hexagonal settings of this structure can be obtained with the option ––hex.

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:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & =&0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & =&0 \mathbf{\hat{x}} + 0 \mathbf{\hat{y}} + 0 \mathbf{\hat{z}} & \left(1a\right) & \mbox{Ca} \\ \mathbf{B}_{2} & =&x_{2} \, \mathbf{a}_{1}- x_{2} \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& =&\left(\frac12 x_{2} + \frac34\right) \, a \, \mathbf{\hat{x}}- \frac1{4\sqrt3} \left(1 + 6 x_{2}\right) \, a \, \mathbf{\hat{y}}+ \frac16 \, c \, \mathbf{\hat{z}}& \left(6g\right) & \mbox{C} \\ \mathbf{B}_{3} & =&\frac12 \, \mathbf{a}_{1}+ x_{2} \, \mathbf{a}_{2}- x_{2} \, \mathbf{a}_{3}& =&\left(\frac12 x_{2} + \frac14\right) \, a \, \mathbf{\hat{x}}- \frac1{4\sqrt3} \left(1 - 6 x_{2}\right) \, a \, \mathbf{\hat{y}}+ \frac16 \, c \, \mathbf{\hat{z}}& \left(6g\right) & \mbox{C} \\ \mathbf{B}_{4} & =&- x_{2} \, \mathbf{a}_{1}+ \frac12 \, \mathbf{a}_{2}+ x_{2} \, \mathbf{a}_{3}& =&- x_{2} \, a \, \mathbf{\hat{x}}+ \frac1{2\sqrt3} \, a \, \mathbf{\hat{y}}+ \frac16 \, c \, \mathbf{\hat{z}}& \left(6g\right) & \mbox{C} \\ \mathbf{B}_{5} & =&- x_{2} \, \mathbf{a}_{1}+ x_{2} \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& =&\left(\frac34 - \frac12 x_{2}\right) \, a \, \mathbf{\hat{x}}- \frac1{4\sqrt3} \left(1 - 6 x_{2}\right) \, a \, \mathbf{\hat{y}}+ \frac16 \, c \, \mathbf{\hat{z}}& \left(6g\right) & \mbox{C} \\ \mathbf{B}_{6} & =&\frac12 \, \mathbf{a}_{1}- x_{2} \, \mathbf{a}_{2}+ x_{2} \, \mathbf{a}_{3}& =&\left(\frac14 - \frac12 x_{2}\right) \, a \, \mathbf{\hat{x}}- \frac1{4\sqrt3} \left(1 + 6 x_{2}\right) \, a \, \mathbf{\hat{y}}+ \frac16 \, c \, \mathbf{\hat{z}}& \left(6g\right) & \mbox{C} \\ \mathbf{B}_{7} & =&x_{2} \, \mathbf{a}_{1}+ \frac12 \, \mathbf{a}_{2}- x_{2} \, \mathbf{a}_{3}& =&x_{2} \, a \, \mathbf{\hat{x}}+ \frac1{2\sqrt3} \, a \, \mathbf{\hat{y}}+ \frac16 \, c \, \mathbf{\hat{z}}& \left(6g\right) & \mbox{C} \\ \end{array} \]

References

  • N. Emery, C. Hérold, M. d'Astuto, V. Garcia, C. Bellin, J. F. Mareché, P. Lagrange, and G. Loupias, Superconductivity of Bulk CaC6, Phys. Rev. Lett. 95, 087003 (2005), doi:10.1103/PhysRevLett.95.087003.

Geometry files


Prototype Generator

aflow --proto=A6B_hR7_166_g_a --params=

Species:

Running:

Output: