Hydrogen Clathrate Structures in Uranium Hydrides at High Pressures.

Room-temperature superconductivity has always been an area of intensive research. Recent findings of clathrate metal hydrides structures have opened up the doors for achieving room-temperature superconductivity in these materials. Here, we report first-principles calculations for stable H-rich clathrate structures of uranium hydrides at high pressures. The clathrate uranium hydrides contain H cages with stoichiometries of H, H, and H, in which H atoms are bonded covalently to other H atoms, and U atoms occupy the centers of the cages. Especially, a UH clathrate structure containing H cages is predicted to have an estimated higher than 77 K at high pressures.