S-III Structure: A_tI16_142_f-001
| Prototype | S |
| AFLOW prototype label | A_tI16_142_f-001 |
| ICSD | none |
| Pearson symbol | tI16 |
| Space group number | 142 |
| Space group symbol | $I4_1/acd$ |
| AFLOW prototype command |
aflow --proto=A_tI16_142_f-001
--params=$a, \allowbreak c/a, \allowbreak x_{1}$ |
Other compounds with this structure
Se (Se-VII, prepared at 450K and 20 GPa)
- The S-III phase is found when sulfur is pressurized above 36 GPa at 300K. At 300K it is stable up to 83 GPa. This data was taken at 12 GPa and 300K.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&- \frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{2}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}- \frac{1}{2}a \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}\\\mathbf{a_{3}}&=&\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}a \,\mathbf{\hat{y}}- \frac{1}{2}c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $\left(x_{1} + \frac{3}{8}\right) \, \mathbf{a}_{1}+\left(x_{1} + \frac{1}{8}\right) \, \mathbf{a}_{2}+\left(2 x_{1} + \frac{1}{4}\right) \, \mathbf{a}_{3}$ | = | $a x_{1} \,\mathbf{\hat{x}}+a \left(x_{1} + \frac{1}{4}\right) \,\mathbf{\hat{y}}+\frac{1}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{2}}$ | = | $- \left(x_{1} - \frac{3}{8}\right) \, \mathbf{a}_{1}- \left(x_{1} - \frac{1}{8}\right) \, \mathbf{a}_{2}- \left(2 x_{1} - \frac{1}{4}\right) \, \mathbf{a}_{3}$ | = | $- a x_{1} \,\mathbf{\hat{x}}- a \left(x_{1} - \frac{1}{4}\right) \,\mathbf{\hat{y}}+\frac{1}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{3}}$ | = | $\left(x_{1} + \frac{1}{8}\right) \, \mathbf{a}_{1}- \left(x_{1} - \frac{3}{8}\right) \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ | = | $- a \left(x_{1} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+a \left(x_{1} + \frac{1}{4}\right) \,\mathbf{\hat{y}}- \frac{1}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{4}}$ | = | $- \left(x_{1} - \frac{1}{8}\right) \, \mathbf{a}_{1}+\left(x_{1} + \frac{3}{8}\right) \, \mathbf{a}_{2}+\frac{3}{4} \, \mathbf{a}_{3}$ | = | $a \left(x_{1} + \frac{1}{2}\right) \,\mathbf{\hat{x}}- a \left(x_{1} - \frac{1}{4}\right) \,\mathbf{\hat{y}}- \frac{1}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{5}}$ | = | $- \left(x_{1} - \frac{5}{8}\right) \, \mathbf{a}_{1}- \left(x_{1} - \frac{7}{8}\right) \, \mathbf{a}_{2}- \left(2 x_{1} - \frac{3}{4}\right) \, \mathbf{a}_{3}$ | = | $- a \left(x_{1} - \frac{1}{2}\right) \,\mathbf{\hat{x}}- a \left(x_{1} - \frac{1}{4}\right) \,\mathbf{\hat{y}}+\frac{3}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{6}}$ | = | $\left(x_{1} + \frac{5}{8}\right) \, \mathbf{a}_{1}+\left(x_{1} + \frac{7}{8}\right) \, \mathbf{a}_{2}+\left(2 x_{1} + \frac{3}{4}\right) \, \mathbf{a}_{3}$ | = | $a \left(x_{1} + \frac{1}{2}\right) \,\mathbf{\hat{x}}+a \left(x_{1} + \frac{1}{4}\right) \,\mathbf{\hat{y}}+\frac{3}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{7}}$ | = | $- \left(x_{1} - \frac{7}{8}\right) \, \mathbf{a}_{1}+\left(x_{1} + \frac{5}{8}\right) \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ | = | $a x_{1} \,\mathbf{\hat{x}}- a \left(x_{1} - \frac{1}{4}\right) \,\mathbf{\hat{y}}+\frac{5}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
| $\mathbf{B_{8}}$ | = | $\left(x_{1} + \frac{7}{8}\right) \, \mathbf{a}_{1}- \left(x_{1} - \frac{5}{8}\right) \, \mathbf{a}_{2}+\frac{1}{4} \, \mathbf{a}_{3}$ | = | $- a x_{1} \,\mathbf{\hat{x}}+a \left(x_{1} + \frac{1}{4}\right) \,\mathbf{\hat{y}}+\frac{5}{8}c \,\mathbf{\hat{z}}$ | (16f) | S I |
References
- O. Degtyareva, E. Gregoryanz, M. Somayazulu, P. Dera, H. Mao, and R. J. Hemley, Novel chain structures in group VI elements, Nat. Mater. 4, 152–155 (2005), doi:10.1038/nmat1294.
Prototype Generator
aflow --proto=A_tI16_142_f --params=$a,c/a,x_{1}$