Comment on “Correlation and relativistic effects in U metal and U-Zr alloy: Validation ofab initioapproaches”

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

“…All the lattice parameters of the GGA methods (GGA-PBE, GGA-RPBE, and GGA-PW91) are close to the experimental values ( = 2.836Å, = 5.867Å, and = 4.955Å). The similar investigations also can be seen in Söderlind's research [12]. After the original cell of the uranium being fully relaxed, the calculated total energy of the original cell is −5615.273 eV (GGA-PBE) which is the lowest total energy of all the three GGA methods.…”

“…It is indicated that the first three layers contribute dominantly to the surface properties of uranium. As shown in Table 3, in the same surface configurations, 12 has much larger shrinkage than 23 due to the interaction of uranium atoms, which strengthens the interaction between the surface and subsurface, and finally narrows the distances between all the uranium layers. The decreases of surface distance (Δ 12 / 0 , Δ 23 / 0 ) become much smaller as the surface layers increase.…”

“…He found that the early actinides are governed predominantly by fully active 5f bonding [11]. The DFT-PAW method was actually able to reproduce the bonding and electronic structure of alpha uranium [12]. Zhang [13] and Michael [14] et al also investigated the actinide metals by computer simulations.…”

“…Hereafter, in this paper, we focused on the investigation of different surfaces of alpha uranium bulk using the most precise GGA methods. These GGA methods have been previously shown to treat the ground state properties of the light actinides [12]. The surface energies, work function, bulk modulus, elastic constants, and electronic state density of seven basic alpha uranium surfaces were calculated and the results are presented in Section 3.…”

“…These reactions take place on the surface and are mainly determined by the nature of the 5f electrons of the surface atoms. The effect of 5f electrons of early actinide metals (Th-Np) has attracted considerable attention for years [11][12][13][14]. There are a lot of cases about the surface properties of uranium and uranium compound in experiments [15,16].…”