Marcasite (FeS$_{2}$, $C18$) Structure: AB2_oP6_58_a_g-003
| Prototype | FeS$_{2}$ |
| AFLOW prototype label | AB2_oP6_58_a_g-003 |
| Strukturbericht designation | $C18$ |
| Mineral name | marcasite |
| ICSD | 109374 |
| Pearson symbol | oP6 |
| Space group number | 58 |
| Space group symbol | $Pnnm$ |
| AFLOW prototype command |
aflow --proto=AB2_oP6_58_a_g-003
--params=$a, \allowbreak b/a, \allowbreak c/a, \allowbreak x_{2}, \allowbreak y_{2}$ |
Other compounds with this structure
CoAs$_{2}$, CoTe$_{2}$, CrSb$_{2}$, CuS$_{2}$, FeAs$_{2}$, FeP$_{2}$, FeSb$_{2}$, FeSe$_{2}$, FeTe$_{2}$, NiAs$_{2}$ (rammelsbergite), NiS$_{2}$, NiSb$_{2}$, OsAs$_{2}$, OsP$_{2}$, OsSb$_{2}$, RuAs$_{2}$, RuP$_{2}$, RuSb$_{2}$, RuTe$_{2}$
- FeS$_{2}$ has been found in at least four forms:
- a triclinic ($P1$ #1) phase,
- a low temperature orthorhombic pyrite phase,
- the most commonly observed state, cubic pyrite ($C2$), and
- orthorhombic martensite ($C18$) (this structure).
- Hydrophilite (CaCl$_{2}$, $C35$), $\eta$–Fe$_{2}$C, and marcasite (FeS$_{2}$, $C18$) have the same AFLOW prototype label, AB2_oP6_58_a_g. They are generated by the same symmetry operations with different sets of parameters (
--params) specified in their corresponding CIF files.
\[ \begin{array}{ccc}
\mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&b \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}}
\end{array}\]
Basis vectors
| Lattice coordinates | Cartesian coordinates | Wyckoff position | Atom type | |||
|---|---|---|---|---|---|---|
| $\mathbf{B_{1}}$ | = | $0$ | = | $0$ | (2a) | Fe I |
| $\mathbf{B_{2}}$ | = | $\frac{1}{2} \, \mathbf{a}_{1}+\frac{1}{2} \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $\frac{1}{2}a \,\mathbf{\hat{x}}+\frac{1}{2}b \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (2a) | Fe I |
| $\mathbf{B_{3}}$ | = | $x_{2} \, \mathbf{a}_{1}+y_{2} \, \mathbf{a}_{2}$ | = | $a x_{2} \,\mathbf{\hat{x}}+b y_{2} \,\mathbf{\hat{y}}$ | (4g) | S I |
| $\mathbf{B_{4}}$ | = | $- x_{2} \, \mathbf{a}_{1}- y_{2} \, \mathbf{a}_{2}$ | = | $- a x_{2} \,\mathbf{\hat{x}}- b y_{2} \,\mathbf{\hat{y}}$ | (4g) | S I |
| $\mathbf{B_{5}}$ | = | $- \left(x_{2} - \frac{1}{2}\right) \, \mathbf{a}_{1}+\left(y_{2} + \frac{1}{2}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $- a \left(x_{2} - \frac{1}{2}\right) \,\mathbf{\hat{x}}+b \left(y_{2} + \frac{1}{2}\right) \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (4g) | S I |
| $\mathbf{B_{6}}$ | = | $\left(x_{2} + \frac{1}{2}\right) \, \mathbf{a}_{1}- \left(y_{2} - \frac{1}{2}\right) \, \mathbf{a}_{2}+\frac{1}{2} \, \mathbf{a}_{3}$ | = | $a \left(x_{2} + \frac{1}{2}\right) \,\mathbf{\hat{x}}- b \left(y_{2} - \frac{1}{2}\right) \,\mathbf{\hat{y}}+\frac{1}{2}c \,\mathbf{\hat{z}}$ | (4g) | S I |
References
- M. Rieder, J. C. Crelling, O. Šustai, M. Drábek, Z. Weiss, and M. Klementová, Arsenic in iron disulfides in a brown coal from the North Bohemian Basin, Czech Republic, Int. J. Coal Geology 71, 115–121 (2007), doi:10.1016/j.coal.2006.07.003.
Found in
- R. T. Downs and M. Hall-Wallace, The American Mineralogist Crystal Structure Database, Am. Mineral. 88, 247–250 (2003).
Prototype Generator
aflow --proto=AB2_oP6_58_a_g --params=$a,b/a,c/a,x_{2},y_{2}$