Phonon Life-times from first principles self consistent lattice dynamics

TL;DR

This paper introduces a new first-principles method for calculating phonon lifetimes that overcomes limitations of existing approaches, enabling analysis of dynamically unstable structures with improved efficiency.

Contribution

A novel self-consistent lattice dynamical method for phonon lifetime calculation applicable to structures unstable at zero temperature.

Findings

Successfully applied to bcc phases of Li, Na, Ti, and Zr.

Demonstrates effectiveness beyond zero-temperature stability assumptions.

Potentially more efficient than molecular dynamics methods.

Abstract

Phonon lifetime calculations from first principles usually rely on time consuming molecular dynamics calculations, or density functional perturbation theory (DFPT) where the zero temperature crystal structure is assumed to be dynamically stable. Here a new and effective method for calculating phonon lifetimes from first principles is presented, not limited to crystal structures stable at 0 K, and potentially much more effective than most corresponding molecular dynamics calculations. The method is based on the recently developed self consistent lattice dynamical method and is here tested by calculating the bcc phase phonon lifetimes of Li, Na, Ti and Zr, as representative examples.