Modulated Structure Calculated for Superconducting Hydrogen Sulfide

Compression of hydrogen sulfide using first principles metadynamics and molecular dynamics calculations revealed a modulated structure with high proton mobility which exhibits a diffraction pattern matching well with experiment. The structure consists of a sublattice of rectangular meandering SH − chains and molecular‐like H 3 S + stacked alternately in tetragonal and cubic slabs forming a long‐period modulation. The novel structure offers a new perspective on the possible origin of the superconductivity at very high temperatures in which the conducting electrons in the SH chains are perturbed by the fluxional motions of the H 3 S resulting in strong electron‐phonon coupling.