• Oscar Guerrero

In this writing, I will present a fast-efficient computational Pseudo code to find acoustic phonon instabilities in crystals. The code uses the stress-strain relations to numerical find sound velocities in terms of second-order elastic constants for various wave modes in uniaxial and hydrostatically compressed crystals for a given wave direction < 𝒌 >. I use Tantalum and Copper as the testing materials. The results are compared with Molecular dynamics simulations using the EAM potential formalism, DFT calculations via VASP and lattice stability function uniaxial compression by determining the phonon-dispersion relation over the entire BZ. The implementation of the code is discussed using the free, open-source software OCTAVE and the symbolic program MATHEMATICA.

Phonon instability, speed sound, Molecular Dynamics, Single Crystal Metals

"A Numerical algorithm for the prediction of pressure induce phonon instabilities via computational modeling of Acoustic wave propagation in isotropic and anisotropic crystals", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.10, Issue 1, page no.b59-b81, January-2023, Available :http://www.jetir.org/papers/JETIR2301110.pdf

"A Numerical algorithm for the prediction of pressure induce phonon instabilities via computational modeling of Acoustic wave propagation in isotropic and anisotropic crystals", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.10, Issue 1, page no. ppb59-b81, January-2023, Available at : http://www.jetir.org/papers/JETIR2301110.pdf