JOURNAL OF PHYSICS-CONDENSED MATTER, vol.19, no.43, 2007 (SCI-Expanded)
We have studied the structural, elastic, electronic, thermodynamical and vibrational properties of LaAs and LaP in the rock-salt (B1) structure by performing ab initio calculations within the local-density approximation (LDA). Some basic physical properties, such as the lattice constant, bulk modulus, cohesive energy, second-order elastic constants (C-ij), the electronic band structures, and phonon frequencies, are calculated and compared with the available experimental and other theoretical values. In order to gain further information, we have, also, predicted the Young's modulus, Poisson's ratio (nu), anisotropy factor ( A), sound velocities, and Debye temperature (theta(D)), and reasonable values have been found. We also present the temperature-dependent behaviour of some thermodynamical properties such as entropy and heat capacity for these compounds in the B1 phase.