The AFLOW Library of Crystallographic Prototypes: Part 2 (1806.07864v1)

Abstract: Materials discovery via high-throughput methods relies on the availability of structural prototypes, which are generally decorated with varying combinations of elements to produce potential new materials. To facilitate the automatic generation of these materials, we developed $\textit{The AFLOW Library of Crystallographic Prototypes}$ $\unicode{x2014}$ a collection of crystal prototypes that can be rapidly decorated using the AFLOW software. Part 2 of this work introduces an additional 302 crystal structure prototypes, including at least one from each of the 138 space groups not included in Part 1. Combined with Part 1, the entire library consists of 590 unique crystallographic prototypes covering all 230 space groups. We also present discussions of enantiomorphic space groups, Wigner-Seitz cells, the two-dimensional plane groups, and the various different space group notations used throughout crystallography. All structures $\unicode{x2014}$ from both Part 1 and Part 2 $\unicode{x2014}$ are listed in the web version of the library available at aflow.org/CrystalDatabase.

An In-Depth Overview of Crystal Structure Cataloguing and Its Importance in Materials Science

The paper "The AFLOW Library of Crystallographic Prototypes: Part 2" is the second instaLLMent in an effort to develop a comprehensive resource for the automatic generation of material structures. The research focuses on expanding the library of crystallographic prototypes, essential for high-throughput computational materials discovery, by introducing 302 new structure prototypes, complementing the initial 288 from Part 1.

Significance of High-Throughput Computing

High-throughput computing has revolutionized material science by enabling the exploration of vast material spaces. It has facilitated significant advancements, such as the prediction of novel materials with desired properties, including metallic glasses and high-entropy oxides. The integration of thermomechanical and symmetry analyses into these frameworks allows researchers to calculate and store a variety of material properties efficiently. The burgeoning databases like NoMaD, Materials Project, and OQMD are instrumental in this context, offering repositories that aid further research and material discovery.

The Role of Structural Prototypes

The primary focus of this paper is on crystalline structure prototypes – standardized representations of materials used as inputs for computational methods. These prototypes provide the foundation for designing new materials by substituting different atomic constituents into known structures. This systematic approach increases the likelihood of discovering synthesizable materials with desired properties. However, accessibility to such structured data has been limited, prompting the need for an easily accessible library like AFLOW.

Expanding the AFLOW Library

The expansion of the AFLOW library to include an additional 302 prototypes ensures diversity by encompassing structures from 138 additional space groups. The library now includes 590 unique crystallographic prototypes, covering all 230 space groups. This completion is vital for offering comprehensive structural representations essential for the high-throughput computational tasks that underpin modern materials science research.

Architectural Foundations and Technical Details

The paper provides detailed methodologies for constructing these prototypes, including the definitions of primitive and conventional cells across various crystal systems. Moreover, the paper illustrates the use of Wigner-Seitz cells, emphasizing their utility in defining unit cells clearly. The research also explores the two-dimensional plane groups, offering an essential perspective for layered materials like graphene.

Space Group Symbology

An integral component of the paper is the discussion on various space group notations including the Hermann-Mauguin, Hall, and Schӧnflies symbols, each serving a different aspect of crystallography. These standardizations are critical for ensuring consistent communication among researchers about crystal structures and symmetries.

Practical Implications and Future Directions

This library not only serves as a pivotal tool for computational materials scientists but also lays the groundwork for future extensions in the realms of automated materials design. As high-throughput methods continue to evolve, the library can facilitate the rapid deployment of computational workflows aimed at exploring novel material spaces. The expansion of such libraries promises potential breakthroughs in the development of materials with unprecedented properties.

In conclusion, "The AFLOW Library of Crystallographic Prototypes: Part 2" significantly contributes to the infrastructure necessary for advancing computational material science. By making a comprehensive set of structural prototypes available, the research fosters innovation in the design and discovery of new materials, which is essential for meeting the scientific and technological challenges of tomorrow.