Ab initio study of Ti3Si0.5Ge0.5C2 under pressure

Structural and electronic properties of Ti3Si0.5Ge0.5C2 under pressure up to 80 GPa are studied by means of first principles calculation based on density functional theory (DFT). The total energy, lattice parameters and atomic positions are employed to investigate the structural changes under pressure. Within the local density approximation (LDA) used in the calculation, the obtained equilibrium volume and the bulk modulus are in good agreement with the experimental values. The compression is almost isotropic up to 15 GPa, but above this pressure a certain degree of anisotropy appears. The calculated electronic properties reveals that the band structure and the density of states (DOS) do not present big changes under pressure. However, it is noticeable a decrease of the DOS at the Fermi level under pressure, which could result in a reduction of the electrical conductivity at high pressure. (c) 2006 Elsevier Ltd. All rights reserved.