  As an A-site-vacant perovskite-type oxide, ReO3 undergoes sequential
pressure-driven structural transitions associated with the rotation of ReO6
octahedra. The rhombohedral-I phase stable in the pressure range of 12-38 GPa
is featured by a lattice of nearly close-packed oxygen layers intercalated with
Re cations, in reminiscent of the recently discovered superhydride
superconductors. A combined study of first-principles calculations and
transport measurements under high pressures enabled us to discover
superconductivity in the rhombohedral-I phase showing a dome-shaped Tc(P) with
a maximum Tc of 17 K at about 30 GPa. In addition to the enhanced density of
states at the Fermi level compared to that of the ambient phase, the
low-frequency vibrations of hexagonal-close-packed oxygen lattice significantly
strengthen the electron-phonon coupling, which is responsible for observed
superconductivity with a relatively high Tc. The present work thus establishes
a rare case among oxide superconductors that the light-element oxygen lattice
plays a crucial role in inducing superconductivity.
