2015 Fiscal Year Annual Research Report
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
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| Research Institution | Nagoya University |
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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)
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| 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
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| Project Period (FY) |
2015-11-09 – 2017-03-31
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| Keywords | computational chemistry / ionic liquids / quantum mechanics / DFTB |
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| Outline of Annual Research Achievements |
In the first phase of the project, preliminary studies on ionic liquids were undertaken. Based on previous works, an algorithm for generating cartesian coordinates was modified to efficiently generate molecular clusters. Using this algorithm, structures of an ionic liquid consisting of methyl-, ethyl- and butylmethylimmidazolium cations and nitrate anions could be generated with improved efficiency. These structures were optimized, using the density-functional tight-binding method. The electronic structures of these structures have been investigated using the density-functional tight-binding method as well as the fragment-molecular-orbital density-functional tight-binding method. The energies of the highest-occupied molecular orbitals and lowest-unoccupied molecular orbitals have been compared with an experimental study, that used photoelectron spectroscopy to investigate the redox properties of this ionic liquid system and its dependence on the length of the alkyl-side chain. The dependence of these energies on the size of the ionic liquid molecular clusters and the length of the alkyl-side chain is currently being investigated.The geometries as well as electronic structures of these ionic liquids are currently being prepared for an in-depth comparison of linear-scaling quantum-mechanical methods, including the aforementioned fragment-molecular-orbital density-functional tight-binding method, the divide-and-conquer desnity-functional tight-binding method, among others.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
One year has passed from the submission of the proposal to the beginning of the funding. During that period, new experiences have emerged. For example, the proposed combination of the Extended Lagrangian Born-Oppenheimer Molecular Dynamics method with the Fragment-Molecular-Orbital method does likely not lead to the hoped increase in speed of the Molecular Dynamics simulation, because it is likely, that the rate-limiting step of the Fragment-Molecular Orbital method is not influenced by this combination. In addition, preliminary requirements, that are necessary to perform the proposed work, such as the efficient generation of molecular clusters, have surprisingy been a challenge. Furthermore, in the mean time new, challenging collaboration projects have been started, which took time to proceed.
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| Strategy for Future Research Activity |
The core of the project still is the application of different Linear scaling quantum mechanical methods to the systems of Ionic Liquids. The plan will be applied as proposed, but the scope might have to be limited to more feasabile goals.
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Research Products
(2 results)
