ThH2 ($L'2_{b}$) Structure: A2B_tI6_139_d_a

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Prototype : ThH2
AFLOW prototype label : A2B_tI6_139_d_a
Strukturbericht designation : $L'2_{b}$
Pearson symbol : tI6
Space group number : 139
Space group symbol : $\mbox{I4/mmm}$
AFLOW prototype command : aflow --proto=A2B_tI6_139_d_a
--params=
$a$,$c/a$


Other compounds with this structure

  • SiPt2, TiH2, ZrH2

  • This structure was given the extended Strukturbericht label $L'2_{b}$ by (Pearson, 1967). It did not appear in the original Strukturbericht label. We had previously followed (Villars, 1991) and (Westbrook, 1995) and gave it the label $L'2$, however this conflicts with the label for the $L'2_{0}$ “martensite” structure, so we will now use the original label.

Body-centered Tetragonal primitive vectors:

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

Basis vectors:

\[ \begin{array}{ccccccc} & & \mbox{Lattice Coordinates} & & \mbox{Cartesian Coordinates} &\mbox{Wyckoff Position} & \mbox{Atom Type} \\ \mathbf{B}_{1} & =&0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & =&0 \mathbf{\hat{x}} + 0 \mathbf{\hat{y}} + 0 \mathbf{\hat{z}} & \left(2a\right) & \mbox{Th} \\ \mathbf{B}_{2} & =&\frac34 \, \mathbf{a}_{1}+ \frac14 \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& =&\frac12 \, a \, \mathbf{\hat{y}}+ \frac14 \, c \, \mathbf{\hat{z}}& \left(4d\right) & \mbox{H} \\ \mathbf{B}_{3} & =&\frac14 \, \mathbf{a}_{1}+ \frac34 \, \mathbf{a}_{2}+ \frac12 \, \mathbf{a}_{3}& =&\frac12 \, a \, \mathbf{\hat{x}}+ \frac14 \, c \, \mathbf{\hat{z}}& \left(4d\right) & \mbox{H} \\ \end{array} \]

References

  • R. E. Rundle, C. G. Shull, and E. O. Wollan, The crystal structure of thorium and zirconium dihydrides by X–ray and neutron diffraction, Acta Cryst. 5, 22–26 (1952), doi:10.1107/S0365110X52000071.
  • W. B. Pearson, A Handbook of Lattice Spacings and Structures of Metals and Alloys, Volume 2, no. N.R.C. No. 8752 in International Series of Monographs on Metal Physics and Physical Metallurgy (Pergamon Press, Oxford, London, Edinburgh, New York, Paris, Frankfort, 1967).
  • P. Villars and L. Calvert, Pearson's Handbook of Crystallographic Data for Intermetallic Phases (ASM International, Materials Park, OH, 1991), 2nd edn.
  • J. H. Westbrook and R. L. Fleischer, eds., Intermetallic Compounds – Principles and Practice (John Wiley & Sons, Ltd., Chichester, England, 1995). Two Volumes.

Geometry files


Prototype Generator

aflow --proto=A2B_tI6_139_d_a --params=

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