We have used first-principles calculations to study the structural, electronic, and thermodynamic properties of the three known forms of Rh-S chalcogenides: Rh2S3, Rh3S4, and Rh17S15. Only the first of these materials of interest for catalysis had been studied previously within this approach. We find that Rh17S15 crystallizes in a {\em Pm}\={3}{\em m} centrosymmetric structure, as believed experimentally but never confirmed. We show band structures and densities of states for these compounds. Finally, we also investigated the ground state structure of solid sulfur (α-S), one of the few elements that represents a challenge for full first-principles calculations due to its demanding 128-atom unit cell and dispersion interactionis between S8 units.
@article{arxiv.0908.1625,
title = {A first-principles characterization of the structure and electronic structure of $\alpha$-S and Rh-S chalcogenides},
author = {Oswaldo Diéguez and Nicola Marzari},
journal= {arXiv preprint arXiv:0908.1625},
year = {2011}
}