Diche Meriem2023-09-052023-09-052023-06-25http://10.10.1.6:4000/handle/123456789/3730In this work, we present a first principles study on the vibrational properties of the ternary alloy 𝐵𝑁𝑥𝑃(1−𝑥) in the zinc blende (B3) phase. In all the study, we have used ab-initio calculations based on the Density Functional Theory (DFT) combined with the pseudo-potentials method. The resolution of the Kohn-Sham equations is performed self-consistently by using a plane wave basis as implanted in the ABINIT code. For the exchange and correlation potential term, we have studied the effects by using LDA (Local Density Approximation).frab-initio calculus, DFT, pseudo-potentials, VCA, phonons frequencies, 𝐵𝑁𝑥𝑃(1−𝑥).Thesis