AFLOW-QHA3P: Robust and automated method to compute thermodynamic properties of solids

TL;DR

AFLOW-QHA3P introduces a fast, reliable, and automated method for calculating thermodynamic properties of solids using only three phonon calculations, streamlining high-throughput materials research.

Contribution

It presents the 3-phonons quasi-harmonic approximation (QHA) method, enabling efficient thermodynamic property calculations with minimal computational effort.

Findings

The method accurately predicts thermal expansion, specific heat, enthalpy, and bulk modulus.

Results agree with standard and self-consistent QHA methods and experimental data.

The approach is integrated into the open-source AFLOW framework for automation.

Abstract

Accelerating the calculations of finite-temperature thermodynamic properties is a major challenge for rational materials design. Reliable methods can be quite expensive, limiting their effective applicability in autonomous high-throughput workflows. Here, the 3-phonons quasi-harmonic approximation (QHA) method is introduced, requiring only three phonon calculations to obtain a thorough characterization of the material. Leveraging a Taylor expansion of the phonon frequencies around the equilibrium volume, the method efficiently resolves the volumetric thermal expansion coefficient, specific heat at constant pressure, the enthalpy, and bulk modulus. Results from the standard QHA and experiments corroborate the procedure, and additional comparisons are made with the recently developed self-consistent QHA. The three approaches - 3-phonons, standard, and self- consistent QHAs - are all included within the automated, open-source framework AFLOW, allowing automated determination of properties with various implementations within the same framework.