STRUCTURAL, ELECTRONIC AND PHONON PROPERTIES OF LaX COMPOUNDS (X = P, As)

The structural, electronic and phonon properties of the LaP and LaAs compounds in NaCl (B1) and CsCl (B2) structures are studied by means of density functional theory within the generalized gradient approximation. The calculated lattice constants, static bulk modulus and first-order pressure derivative of the bulk modulus are reported in both B1 and B2 structures and compared with previous experimental and theoretical calculations. Band structure and density of states calculations are carried out for LaP and LaAs. Then, a linear-response approach to the density functional theory is used to derive the phonon frequencies and density of states.