Mott vs Kondo: Influence of Various Density Functional Based Methods on the Ce Isostructural Phase Transition Mechanism

TL;DR

This study evaluates various density functional methods to understand the mechanisms behind cerium's gamma to alpha phase transition, highlighting how different approaches capture the physics of f-electron localization and volume collapse.

Contribution

It provides a comprehensive comparison of GGA, MetaGGA, and Hybrid functionals in modeling cerium's phase transition and analyzes the underlying physics driving this transformation.

Findings

Certain functionals accurately predict experimental volume changes.

Mechanisms align with Mott and Kondo physics debates.

Insights into the role of electron localization in phase transition.

Abstract

The cerium iso-structural phase transition (gamma to alpha) is dominated by f-electron localization changes that results in a magnetic ordering change and a volume collapse. Generally, these physics are difficult to capture with ab initio and first principles methods. However, previous works have shown various methods to be successful in predicting at least some of the physics of the gamma to alpha phase transition. Therefore, here, we perform a broad survey of density functional based methods across three levels of theory and types of functions (GGA, MetaGGA, and Hybrid functionals) and compare the results, focusing on hydrostatic compression across the phase boundary at zero Kelvin. For the methods that best reproduce experimental results, we directly probe the predicted mechanisms and frame the results in the Mott/Kondo debate, assessing how the underlying methods and assumptions of different functionals can assess the physical drivers in the phase transition, providing insight into the governing dynamics of this unique phase transition.