Atomistic simulation on the structure and lattice vibration of RCo2Al8 (R = La, Ce and Pr)

The structural properties of RCo2Al8 (R = La, Ce and Pr) compounds are simulated by using pair potentials based on ab initio method and lattice-inversion technique. The calculated lattice constants and atomic coordinates are found in good agreement with the experimental values. Further, some simple mechanical properties such as the elastic constants and bulk modulus are investigated for these materials. In particular, the phonon densities of states for RCo2Al8 are first evaluated. A qualitative analysis is carried out with the relevant potentials for the vibrational modes, which makes it possible to predict some properties related to lattice vibration.