# Phonon dispersion measured directly from molecular dynamics simulations

## Description

This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2018) Abstract A method to measure the phonon dispersion of a crystal based on molecular dynamics simulation is proposed and implemented as an extension to an open source classical molecular dynamics simulation code LAMMPS. In the proposed method, the dynamical matrix is constructed by observing the displacements of atoms during molecular dynamics simulation, making use of the fluctuation–dissipation theory. The dynamical matrix can then be employed to compute the phonon spectra by evaluating its eigenvalue... Title of program: FixPhonon, version 1.0 Catalogue Id: AEJB_v1_0 Nature of problem Atoms in solids make ceaseless vibrations about their equilibrium positions, and a collective vibration forms a wave of allowed wavelength and amplitude. The quantum of such lattice vibration is called the phonon, and the so-called "lattice dynamics" is the field of study to find the normal modes of these vibrations. In other words, lattice dynamics examines the relationship between the frequencies of phonons and the wave vectors, i.e., the phonon dispersion. The evaluation of the phonon dispers ... Versions of this program held in the CPC repository in Mendeley Data AEJB_v1_0; FixPhonon, version 1.0; 10.1016/j.cpc.2011.04.019