大規模複雑系に適用可能な新規量子化学計算手法の開発と応用

• Project/Area Number: 15F15778
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 外国
• Research Field: Physical chemistry
• Research Institution: Nagoya University
• Principal Investigator: Irle Stephan 名古屋大学, トランスフォーマティブ生命分子研究所, 教授 (00432336)
• Co-Investigator(Kenkyū-buntansha): WELKE KAI 名古屋大学, トランスフォーマティブ生命分子研究所, 外国人特別研究員
• Project Period (FY): 2015-11-09 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥1,200,000 (Direct Cost: ¥1,200,000); Fiscal Year 2016: ¥300,000 (Direct Cost: ¥300,000); Fiscal Year 2015: ¥900,000 (Direct Cost: ¥900,000)
• Keywords: computational / ionic liquids / quantum mechanics / DFT / computational chemistry / DFTB

Outline of Annual Research Achievements

We investigated structural as well as electronic properties and dynamic features of ionic liquids with the help of fast, state-of-the-art semi-empirical quantum-chemical simulation methods. At the beginning, considerable efforts were undertaken to optimize implementations of existing algorithms to make them applicable to modern parallel computer architecture and enable a fast generation of molecular clusters of ionic liquids with varying constraints. With the help of this algorithm, structures of molecular clusters of ionic liquids consisting of methyl-, ethyl- and butylmethylimmidazolium cations and nitrate anions were generated and prepared for subsequent investigation by quantum-chemical methods. All structures could be successfully optimized using the fragment-molecular-orbital density-functional tight-binding method. After the validity of these structures were verified by comparing to existing simulation studies and experiments, we proceeded to electronic structure calculations. First, we investigated the effect of different alkyl-side chains on the structures of the ionic liquids as well as the effect on the redox properties, especially the HOMO-LUMO gap. On small-sized molecular clusters of ionic liquids, molecular dynamics simulation using the density-functional tight-binding method was performed. To enable more efficient simulations, the extended Lagrangian protocol can be applied to the investigated systems. The results of such calculations provide insight into the structure and dynamics of ionic liquids and a publication on this topic is in preparation.

Research Progress Status

28年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

28年度が最終年度であるため、記入しない。

Research Products

• [Int'l Joint Research] Department of Biology, U. of Washington/Howard Hughes Medical Institute(米国)
• [Int'l Joint Research] Professor Thomas Frauenheim/BCCMS/University of Bremen(Germany)
• [Int'l Joint Research]
• [Journal Article] Cryptic bioactivity capacitated by synthetic hybrid plant peptides (2017)
  • Author(s): Hirakawa Y, Shinohara H, Welke K, Irle S, Matsubayashi Y, Torii KU, Uchida N.
  • Journal Title: Nature Commun. Volume: 8 Issue: 1 Pages: 14318-14318
  • DOI: 10.1038/ncomms14318
  • Peer Reviewed / Open Access / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] A Macrocyclic Fluorophore Dimer with Flexible Linkers: Bright Excimer Emission with Long Fluorescence Lifetime (2016)
  • Author(s): H. Osaki, C.-M. Chou, M. Taki, K. Welke, D. Yokogawa, S. Irle, Y. Sato, T. Higashiyama, S. Saito, A. Fukazawa, S. Yamaguchi
  • Journal Title: Angewandte Chemistry International Edition Volume: 55 Issue: 25 Pages: 7131-7136
  • DOI: 10.1002/anie.201602239
  • Peer Reviewed / Int'l Joint Research