Learning from data to design functional materials without inversion symmetry.

Area of Science:

• Materials Science
• Computational Chemistry
• Solid State Physics

Background:

• Discovering functional materials with specific symmetries, like noncentrosymmetric structures, is crucial but challenging.
• Accelerating the design and discovery process for these materials is a key goal in materials science.

Purpose of the Study:

• To develop and apply an informatics-guided ab initio approach for accelerating the design and discovery of noncentrosymmetric materials.
• To uncover design guidelines for predicting noncentrosymmetric compounds, specifically within the Ruddlesden-Popper oxide family.

Main Methods:

• Integration of group theory, informatics, and density-functional theory (DFT) calculations.
• Utilizing group theory to identify symmetry-breaking mechanisms (oxygen octahedral rotations, cation ordering).
• Employing informatics tools to screen candidate compositions based on group-theoretical predictions.

Main Results:

• Screened approximately 3,200 compositions, identifying 242 potential noncentrosymmetric compounds.
• Achieved a 25-fold increase in the projected number of known noncentrosymmetric Ruddlesden-Popper oxides.
• Validated predictions for 19 compounds using phonon calculations, with 17 exhibiting noncentrosymmetric ground states, including two potential multiferroics.

Conclusions:

• The developed informatics-guided ab initio approach effectively accelerates the discovery of noncentrosymmetric materials.
• This method enables the rational design of materials with targeted crystal symmetries and functionalities.
• The findings significantly expand the landscape of noncentrosymmetric Ruddlesden-Popper oxides with potential for advanced applications.