Calculation of the physical properties of an isotopic compound of ternary lithium hydride

In this paper, the physical properties, including the lattice constant/coefficient, the density of the compound and that of H (D, T), of an isotopic compound of ternary lithium hydride (LiHxD1-x, LiHxT1-x, LiDxT1-x; x = 0, 0.25, 0.5, 0.75, and 1.0) are calculated by using the density functional theory method within the generalized gradient approximation. Theoretical values show that the density and lattice constants of LiH (D, H) are in good agreement with experimental values. For LiDxT1-x, the theoretical DT density is approximately 0.25 g cm(-3), which is in accordance with the density of DT ice in inertial confinement fusion. Moreover, with the increase of the value x, the lattice parameter almost preserves a constant value while density decreases. These results indicate that LiDxT1-x can increase the capacity of the laser fuel without increasing the bulk and inflation pressure of the ignition target, which proves that LiDxT1-x materials have latent application background in inertial confinement fusion.