An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW\u2014AAPL Automatic Anharmonic Phonon Library

Jose J Plata,Pinku Nath,Cormac Toher,Stefano Curtarolo,Jesús Carrete,Demet Usanmaz,Mark Asta,Marco Fornari,Maarten De Jong,Marco Buongiorno Nardelli

doi:10.1038/s41524-017-0046-7

Abstract

One of the most accurate approaches for calculating lattice thermal conductivity, kappa _ell, is solving the Boltzmann transport equation starting from third-order anharmonic force constants. In addition to the underlying approximations of ab-initio parameterization, two main challenges are associated with this path: high computational costs and lack of automation in the frameworks using this methodology, which affect the discovery rate of novel materials with ad-hoc properties. Here, the Automatic Anharmonic Phonon Library (AAPL) is presented. It efficiently computes interatomic force constants by making effective use of crystal symmetry analysis, it solves the Boltzmann transport equation to obtain kappa _ell, and allows a fully integrated operation with minimum user intervention, a rational addition to the current high-throughput accelerated materials development framework AFLOW. An “experiment vs. theory” study of the approach is shown, comparing accuracy and speed with respect to other available packages, and for materials characterized by strong electron localization and correlation. Combining AAPL with the pseudo-hybrid functional ACBN0 is possible to improve accuracy without increasing computational requirements.

Highlights

Lattice thermal conductivity, κ‘, is the key materials’ property for many technologies and applications, such as thermoelectric materials,[1,2,3] heat sink materials,[4] rewritable density scanningprobe phase-change memories,[5] and thermal medical devices.[6]
Frameworks based on the quasiharmonic Debye model, such as GIBBS14 or the Automatic-Gibbs-Library (AGL),[15,16] are extremely efficient as pre-screening techniques but they lack quantitative accuracy
quasiharmonic approximation (QHA)-based models overall improve accuracy of κ‘, they are far from the results obtained from calculating the anharmonic force constants and solving the associated Boltzmann transport equation (BTE).[8,18]

Summary

INTRODUCTION

Κ‘, is the key materials’ property for many technologies and applications, such as thermoelectric materials,[1,2,3] heat sink materials,[4] rewritable density scanningprobe phase-change memories,[5] and thermal medical devices.[6]. To the best of our knowledge, solving the BTE is the optimal method for systematically and accurately calculating thermal conductivity.[19,20,21] This approach has been successfully applied to many systems during the last decade It has been recently implemented in packages including Phono3py,[22] PhonTS,[23] ALAMODE,[24] and ShengBTE,[25] which compute κ‘ by calculating the anharmonic force constants and solving the BTE. We present Automatic Anharmonic Phonon Library (AAPL), which computes the IFCs and solves the BTE to predict κ‘ as part of the AFLOW high-throughput framework,[28,29,30,31,32,33,34,35,36,37,38,39] automatizing the entire process.

RESULTS AND DISCUSSION

NΩkBT 2

CONCLUSIONS