# Ab initio inversion of structure and the lattice dynamics of a metallic glass: The case of Pd40Ni40P20

## TL;DR

This study uses ab initio methods to determine the structure and lattice dynamics of Pd40Ni40P20 metallic glass, revealing localized vibrational states that could be useful for thermoelectric applications.

## Contribution

First ab initio inversion of structure and lattice dynamics of Pd40Ni40P20 metallic glass using FEAR, providing detailed insights into local order and vibrational behavior.

## Key findings

- Model accurately reproduces experimental signatures
- Identifies a vibrational localized-to-extended transition
- Reveals P atoms exhibit localized rattling motion at high frequencies

## Abstract

In this paper we infer the structure of Pd40Ni40P20 from experimental diffraction data and ab initio interactions using Force Enhanced Atomic Refinement (FEAR). Our model accurately reproduces known experimental signatures of the system and is more efficient than conventional melt-quench schemes. We critically evaluate the local order, carry out detailed comparisons to extended X-ray absorption fine structure (EXAFS) experiments and also discuss the electronic structure. We thoroughly explore the lattice dynamics of the system, and describe a vibrational localized-to-extended transition and discuss the special role of P dynamics. At low energies P is fully contributing to extended modes, but at higher frequencies executes local motion reminiscent of a rattler inside a cage of metal atoms. These highly localized vibrational states suggest a possible utility of these materials for thermoelectric applications.