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

TL;DR

This study uses extensive computational methods to analyze the structure of carbonaceous sulfur hydride at high pressure, finding no evidence of conventional superconductivity in the examined phases.

Contribution

It provides the first comprehensive computational search of C-S-H structures at 250 GPa, challenging the assumption of conventional superconductivity in these materials.

Findings

No van Hove singularities in candidate phases

Only 24 favorable stoichiometries found, all carbon-doped H3S

Electronic density of states analysis rules out conventional superconductivity

Abstract

To elucidate the geometric structure of the putative room temperature superconductor, carbonaceous sulfur hydride, at high pressure, we present the results of an extensive computational structure search of bulk C-S-H at 250 gigapascals. Using the minima hopping structure prediction method coupled to the GPU accelerated Sirius library, more than 17,000 local minima with different stochiometries in large simulation cells were investigated. Only 24 stochiometries are favourable against elemental decomposition, all of them are carbon doped H$_3$S crystals. The absence of van Hove singularities or similar peaks in the electronic density of states of more than 3.000 candidate phases rules out conventional superconductivity in C-S-H at room-temperature.