First-Principles Study of Properties of Alpha Uranium Crystal and Seven Alpha Uranium Surfaces

First-principles calculation based on the GGA methods has been applied to the prediction of the properties of bulk alpha-uranium and seven alpha-uranium surfaces. The number of layers in the slab has great effects on the simulated surface properties. The predicted surface properties are trustworthy when the slab number is nine or more. The surface energies of the seven low index uranium surfaces are in the range from 1.756 to 2.151 J/m(2). The hybrid between the 5f orbital and 6d orbital also has somewhat impacts on the surface energies of uranium.