Learning from Correlations Based on Local Structure: Rare-Earth Nickelates Revisited.

Area of Science:

• Materials Science
• Solid-State Physics
• Computational Chemistry

Background:

• Analyzing local atomic distortions in crystalline materials is crucial for understanding coupled electronic and structural phase transitions.
• Complex materials analysis often requires extensive domain knowledge to identify data limitations and necessity for further experiments or simulations.

Purpose of the Study:

• To introduce descriptive statistics and computational experiments to explicitly recognize data limitations.
• To demonstrate the utility of amplitude (a) and normalized-amplitude (n) distortion-mode property correlation-coefficient heat maps (aCCHMs and nCCHMs) for filling data gaps.

Main Methods:

• Construction and analysis of aCCHMs and nCCHMs using experimental and first-principles symmetry modes.
• Application of the method to rare-earth nickelate perovskites (RNiO3) exhibiting antiferromagnetic and metal-insulator transitions.
• Comparison of crystallographic trends from experimental structures with equilibrium structures from density functional theory.

Main Results:

• The Jahn-Teller distortion mode was found to have a negligible effect on the Néel temperature in RNiO3, contrary to experimental crystallographic trends.
• Discrepancies in conclusions drawn from aCCHMs and nCCHMs highlight the importance of careful interpretation.
• A general method for utilizing CCHMs to screen large structure databases was proposed.

Conclusions:

• aCCHMs and nCCHMs provide valuable insights into material properties and limitations in experimental and computational data.
• The study reveals a discrepancy in the role of the Jahn-Teller distortion mode in rare-earth nickelates, necessitating further investigation.
• The proposed method offers a generalizable approach for materials discovery and analysis.