Crystal structure of Cu₂Se

Chem. Met. Alloys 4 (2011) 200-205

https://doi.org/10.30970/cma4.0184

Lubomir GULAY, Marek DASZKIEWICZ, Oksana STROK, Adam PIETRASZKO

The crystal structures of the low-temperature (space group C2/c, Pearson symbol mS144, a = 7.1379(4) Å, b = 12.3823(7) Å, с = 27.3904(9) Å, β = 94.308º, R_I = 0.0765) and high-temperature (space group Fm-3m, Pearson symbol cF12, a = 5.859(1) Å, R1 = 0.0391) modifications of Cu₂Se were determined by means of X-ray powder and single crystal diffraction. The basic features of the two modifications are similar. The Se atoms are stacked in a close-packed arrangement with the layers in the sequence ABC. The Cu atoms are distributed over all tetrahedral interstices. The positions of Cu are completely ordered in the low-temperature modification, whereas they are disordered in the high-temperature modification.

Unit cell content and arrangement of Cu atoms in/near one Se₄ tetrahedron in HT-Cu₂Se.

Keywords

Cu compounds / Chalcogenides / X-ray single crystal diffraction / X-ray powder diffraction / Crystal structures