Elastic properties and electronic structures of CdCNi3 : A comparative study with MgCNi3

We present a first-principles investigation within the density functional theory on the structural, elastic and electronic properties of CdCNi3 and MgCNi3. The calculated lattice parameters of CdCNi3 and MgCNi3 are in good agreement with the available experimental data. The independent elastic constants are derived from the second derivative of total energy as a function of strain. Furthermore, the elastic modulus and Debye temperatures of CdCNi3 and MgCNi3 are predicted. The Ni-3d states play dominant roles near the Fermi levels for both the two compounds, and there is strong hybridization between Ni-3d and C-2p states. Our results also show that CdCNi3 is quite similar in bonding characteristic to MgCNi3. The spin-polarized calculations and the fixed spin-moment calculations indicate that both CdCNi3 and MgCNi3 have stable non-magnetic state.