AFLOW Prototype: A_tI2_139_a.In
Prototype | : | In |
AFLOW prototype label | : | A_tI2_139_a |
Strukturbericht designation | : | $A6$ |
Pearson symbol | : | tI2 |
Space group number | : | 139 |
Space group symbol | : | $\text{I4/mmm}$ |
AFLOW prototype command | : | aflow --proto=A_tI2_139_a --params=$a$,$c/a$ |
face-centered tetragonal (fct) lattice, a distortion of the fcc lattice. Note that this structure is actually a body-centered tetragonal lattice, since in the tetragonal system there is no distinction between face- and body-centered structures. In the A6 structure, $c/a$ is near the fcc ratio of $\sqrt2$, while in the Aa structure, $c/a$ is near the bcc ratio of $1$. Note that In (A_tI2_139_a, In) and $\alpha$–Pa (A_tI2_139_a, $\alpha$–Pa) have the same AFLOW prototype label. They are generated by the same symmetry operations with different sets of parameters (––params) specified in their corresponding CIF files. (Deshpande, 1969) give the lattice constants for indium using the fct description of the lattice. We have changed this to the bct description, dividing their lattice constant a by $\sqrt{2}$.
Basis vectors:
\[ \begin{array}{ccccccc} & & \text{Lattice Coordinates} & & \text{Cartesian Coordinates} &\text{Wyckoff Position} & \text{Atom Type} \\ \mathbf{B}_{1} & =&0 \, \mathbf{a}_{1} + 0 \, \mathbf{a}_{2} + 0 \, \mathbf{a}_{3} & =&0 \mathbf{\hat{x}} + 0 \mathbf{\hat{y}} + 0 \mathbf{\hat{z}} & \left(2a\right) & \text{In} \\ \end{array} \]