0000000001010792
AUTHOR
C. Muehle
Gold(i) sulfide: Unusual bonding and an unexpected computational challenge in a simple solid
We report the experimental high-pressure crystal structure and equation of state of gold(I) sulfide (Au2S) determined using diamond-anvil cell synchrotron X-ray diffraction. Our data shows that Au2S has a simple cubic structure with six atoms in the unit cell (four Au in linear, and two S in tetrahedral, coordination), no internal degrees of freedom, and relatively low bulk modulus. Despite its structural simplicity, Au2S displays very unusual chemical bonding. The very similar and relatively high electronegativities of Au and S rule out any significant metallic or ionic character. Using a simple valence bond (Lewis) model, we argue that the Au2S crystal possesses two different types of cov…
Structural and vibrational behavior of cubic Cu1.80(3)Se cuprous selenide, berzelianite, under compression
[EN] We have performed an experimental study of the crystal structure and lattice dynamics of cubic Cu1.80(3)Se at ambient temperature and high pressures. Two reversible phase transitions were found at 2.9 and 8.7 GPa. The indexation of the angle-dispersive synchrotron x-ray diffraction patterns suggests a large orthorhombic cell and a monoclinic cell for the high-pressure phases. Raman measurements provide additional information on the local structure. The compressibility of the three ambient temperature phases has been determined and compared to that of other sulphides and selenides.
Gold(i) sulfide: unusual bonding and an unexpected computational challenge in a simple solid† †Electronic supplementary information (ESI) available: Analysis of the pressure-induced amorphization in Au2S and calculated band structure. See DOI: 10.1039/c9sc00371a
Cubic cuprite-type gold(i) sulfide presents unique chemical bonding, which makes it unmodelable using current DFT methods, and a computational challenge.