Efficient exploration of unknown oxides using crystal-structure database and first-principles calculations

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K22057
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 26:Materials engineering and related fields
• Research Institution: Kyoto University
• Principal Investigator: Hayashi Hiroyuki 京都大学, 工学研究科, 助教 (50727419)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: 新規物質探索 / 第一原理計算 / 結晶構造データベース / 形成エネルギー / 凸包線

Outline of Final Research Achievements

The evaluation of thermodynamic stability by first-principles calculations effectively work for the search of unknown compounds. Meanwhile, systematic evaluation is difficult due to the lack of the initial-structure candidates of unknown compounds. In this study, we created hypothetical pseudo-binary oxide models consisting of 33 cations and oxide ions using all the prototype structures in the Inorganic Crystal Structure Database, and evaluated the formation energies by first-principles calculations. As a result, we found that there are many unknown crystal structures with low formation energies as well as many known compounds. Preferential synthesis of these screened crystal structures will improve the efficiency of compound search.

Free Research Field

材料探索

Academic Significance and Societal Importance of the Research Achievements

第一原理計算を基にした熱力学的に安定な未知物質の予測を行う上で、第一原理計算を実行するために適切な初期構造が必要であることが課題の一つに挙げられる。化学組成だけを与えて安定な結晶構造を予測する手法も提案されているが、一つの組成だけでも多くの計算コストを要し、幅広い組成から安定な物質を予測することは現状困難である。本研究では既知の結晶構造データベースにある多様な結晶構造をその初期構造とすることで、幅広い結晶構造の探索を効率的に行う手法を提案できた。