Missing theoretical evidence for conventional room-temperature superconductivity in low-enthalpy structures of carbonaceous sulfur hydrides

To elucidate the geometric structure of the putative room-temperature superconductor, carbonaceous sulfur hydride (C-S-H), at high pressure, we present the results of an extensive computational structure search of bulk C-S-H at 250 GPa. Using the minima hopping structure prediction method coupled to the GPU-accelerated sirius library, more than 17 000 local minima with different stoichiometries in large simulation cells were investigated. Only 24 stoichiometries are favorable against elemental decomposition, and all of them are carbon-doped H3S crystals. The absence of van Hove singularities or similar peaks in the electronic density of states of more than 3000 candidate phases rules out conventional superconductivity in C-S-H at room temperature.