Wrinkled strong quasi-atomic planes caused by partial covalent bonds in α-uranium

Uranium is an important strategic metal widely applied in the nuclear industry. Using first-principles calculations, we investigated the plane slip properties, anisotropy, and bonding characteristics between atoms of α -uranium. We found that the DFT+ U has limited effect on elastic constants and the generalized stacking fault energy of α -uranium, although it includes 5 f electrons. Then we calculated the elastic constants and shear deformation properties using standard DFT, and found that the energy barrier of plane slip of α -uranium is arranged from high to low as: (010)[001] > ( 100 ) [ 010 ] > (100)[001] > ( 001 ) [ 010 ] > ( 001 ) [ 100 ] > (010)[100], which perfectly supports the assumption of wrinkled quasi-atomic planes. At last, electronic structure calculations reveal that the wrinkled strong quasi-atomic planes are composed of metallic bonds with partial covalent character.