Encyclopedia of Crystallographic Prototypes

AFLOW Prototype: A2BC_tP8_129_2c_a_c-002

If you are using this page, please cite:
H. Eckert, S. Divilov, M. J. Mehl, D. Hicks, A. C. Zettel, M. Esters. X. Campilongo and S. Curtarolo, The AFLOW Library of Crystallographic Prototypes: Part 4. Submitted to Computational Materials Science.

Links to this page

https://aflow.org/p/K32Y
or https://aflow.org/p/A2BC_tP8_129_2c_a_c-002
or PDF Version

UCoC$_{2}$ Structure: A2BC_tP8_129_2c_a_c-002

Picture of Structure; Click for Big Picture
Prototype C$_{2}$CoU
AFLOW prototype label A2BC_tP8_129_2c_a_c-002
ICSD 63622
Pearson symbol tP8
Space group number 129
Space group symbol $P4/nmm$
AFLOW prototype command aflow --proto=A2BC_tP8_129_2c_a_c-002
--params=$a, \allowbreak c/a, \allowbreak z_{2}, \allowbreak z_{3}, \allowbreak z_{4}$

Other compounds with this structure

PuFeC$_{2}$,  ScCoC$_{2}$,  ScNiC$_{2}$,  ScFeC$_{2}$,  UFeC$_{2}$,  UNiC$_{2}$


  • (Gem's, 1986) found a small concentration of vacancies on the carbon and cobalt sites: 0.3% on Co (2a), 2% on C-I (2c), and 3% on C-II (2c).

\[ \begin{array}{ccc} \mathbf{a_{1}}&=&a \,\mathbf{\hat{x}}\\\mathbf{a_{2}}&=&a \,\mathbf{\hat{y}}\\\mathbf{a_{3}}&=&c \,\mathbf{\hat{z}} \end{array}\]

Basis vectors

Lattice coordinates Cartesian coordinates Wyckoff position Atom type
$\mathbf{B_{1}}$ = $\frac{3}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}$ = $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}$ (2a) Co I
$\mathbf{B_{2}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}$ = $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}$ (2a) Co I
$\mathbf{B_{3}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+z_{2} \, \mathbf{a}_{3}$ = $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}+c z_{2} \,\mathbf{\hat{z}}$ (2c) C I
$\mathbf{B_{4}}$ = $\frac{3}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}- z_{2} \, \mathbf{a}_{3}$ = $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}- c z_{2} \,\mathbf{\hat{z}}$ (2c) C I
$\mathbf{B_{5}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+z_{3} \, \mathbf{a}_{3}$ = $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}+c z_{3} \,\mathbf{\hat{z}}$ (2c) C II
$\mathbf{B_{6}}$ = $\frac{3}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}- z_{3} \, \mathbf{a}_{3}$ = $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}- c z_{3} \,\mathbf{\hat{z}}$ (2c) C II
$\mathbf{B_{7}}$ = $\frac{1}{4} \, \mathbf{a}_{1}+\frac{1}{4} \, \mathbf{a}_{2}+z_{4} \, \mathbf{a}_{3}$ = $\frac{1}{4}a \,\mathbf{\hat{x}}+\frac{1}{4}a \,\mathbf{\hat{y}}+c z_{4} \,\mathbf{\hat{z}}$ (2c) U I
$\mathbf{B_{8}}$ = $\frac{3}{4} \, \mathbf{a}_{1}+\frac{3}{4} \, \mathbf{a}_{2}- z_{4} \, \mathbf{a}_{3}$ = $\frac{3}{4}a \,\mathbf{\hat{x}}+\frac{3}{4}a \,\mathbf{\hat{y}}- c z_{4} \,\mathbf{\hat{z}}$ (2c) U I

References

  • M. H. Gerss and W. Jeitschko, The crystal structures of ternary actinoid iron (cobalt, nickel) carbides with composition 1:1:2, Mater. Res. Bull. 21, 209–216 (1986), doi:10.1016/0025-5408(86)90208-4.

Prototype Generator

aflow --proto=A2BC_tP8_129_2c_a_c --params=$a,c/a,z_{2},z_{3},z_{4}$

Species:

Running:

Output: