Connection between Mott physics and crystal structure in a series of transition metal binary compounds

Nicola Lanatà,Tsung-Han Lee,Vladan Stevanović,Vladimir Dobrosavljević,Yong-Xin Yao

doi:10.1038/s41524-019-0169-0

Abstract

The choice that a solid system “makes” when adopting a crystal structure (stable or metastable) is ultimately governed by the interactions between electrons forming chemical bonds. Here we analyze six prototypical binary transition metal compounds and shed light on the connection between Mott physics and the behavior of the energy as a function of the spatial arrangement of the atoms in these systems. Remarkably, we find that the main qualitative features of this complex behavior in the Mott phase of these systems can be traced back to the fact that the strong d-electron correlations influence substantially the charge transfer mechanism, which, in turn, controls the electrostatic interactions. This result advances our understanding of the influence of strong correlations on the crystal structure, opens a new avenue for extending structure prediction methodologies to strongly correlated materials, and paves the way for predicting and studying metastability and polymorphism in these systems.

Highlights

Predicting the ground-state structure of crystalline materials, initially thought to be an unsolvable problem, became an active area of research with the advent of efficient numerical implementation of computational total energy methods
In order to investigate these fundamental questions, in this paper we study the influence of strong electronic correlations present in six transition metal binary oxides and chalcogenides (CrO, MnO, FeO, CoO, CoS, and CoSe) in four common crystal structure types shown in Fig. 1
Inclusion of spin polarization at the level of the generalized gradient approximation (GGA) to DFT49 plus U (GGA + U) or local density approximation (LDA) + U straightens out the limitations of unpolarized

Summary

Introduction

Predicting the ground-state structure of crystalline materials, initially thought to be an unsolvable problem, became an active area of research with the advent of efficient numerical implementation of computational total energy methods. In order to investigate these fundamental questions, in this paper we study the influence of strong electronic correlations present in six transition metal binary oxides and chalcogenides (CrO, MnO, FeO, CoO, CoS, and CoSe) in four common crystal structure types shown in Fig. 1 (rocksalt, NiAs-type, zincblende, and wurtzite).

Results

Conclusion