DynaPhoPy: A code for extracting phonon quasiparticles from molecular dynamics simulations

• Published in: Computer physics communications 2017-12, Vol.221, p.221-234
• Main Authors: Carreras, Abel, Togo, Atsushi, Tanaka, Isao
• Format: Article
• Language: English
• Subjects: Anharmonicity; Frequency shift; Linewidth; Molecular dynamics; Phonon
• ISSN: 0010-4655; 1879-2944
• DOI: 10.1016/j.cpc.2017.08.017

We have developed a computational code, DynaPhoPy, that allows us to extract the microscopic anharmonic phonon properties from molecular dynamics (MD) simulations using the normal-mode-decomposition technique as presented by Sun et al. (2014). Using this code we calculated the quasiparticle phonon frequencies and linewidths of crystalline silicon at different temperatures using both of first-principles and the Tersoff empirical potential approaches. In this work we show the dependence of these properties on the temperature using both approaches and compare them with reported experimental data obtained by Raman spectroscopy (Balkanski et al., 1983; Tsu and Hernandez, 1982). Program Title: DynaPhoPy Program Files doi:http://dx.doi.org/10.17632/v493dkxk8r.1 Licensing provisions: MIT License Programming language: Python and C External routines/libraries: phonopy, numpy, matplotlib, scipy and h5py python modules. Optional: FFTW and Cuda Nature of problem: Increasing temperature, a crystal potential starts to deviate from the harmonic regime and anharmonicity is getting to be evident (M. T. Dove, Introduction to lattice dynamics, Vol. 4, Cambridge university press, 1993). To treat anharmonicity, perturbation approach often describes successfully phenomena such as phonon lifetime and lattice thermal conductivity. However it fails when the system contains large atomic displacements. Solution method: Extracting the phonon quasiparticles from molecular dynamics (MD) simulations using the normal-mode-decomposition technique. Restrictions: Quantum effects of lattice dynamics are not considered.