2014 Fiscal Year Annual Research Report
多分散性は構造・ダイナミクス・熱力学の間に影響を与えるか
| Project/Area Number |
13F03707
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| Research Institution | The University of Tokyo |
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Principal Investigator |
田中 肇 東京大学, 生産技術研究所, 教授 (60159019)
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| Co-Investigator(Kenkyū-buntansha) |
INGEBRIGTSEN Trond 東京大学, 生産技術研究所, 外国人特別研究員
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| Project Period (FY) |
2013-04-26 – 2016-03-31
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| Keywords | Roskilde simple liquids / Molecular dynamics / GPU cluster / Size polydispersity |
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| Outline of Annual Research Achievements |
Recently, a new class of liquids was identified, the so-called Roskilde-simple (RS) liquids, and was shown to be simpler than other types of liquids. RS liquids are characterized by having strong correlations between the equilibrium fluctuations of the potential energy U and the virial W at constant volume. RS liquids are, among other things, characterized by having isomorphs and constitute a simplifying property of RS liquids. Isomorphs are curves in the phase diagram of RS liquids along which structure, dynamics, and some thermodynamic quantities are invariant in dimensionless units. In the year 2014, a high-speed graphics card (GPU) cluster was established in ''Tanaka Lab'' and molecular dynamics studies of size polydisperse systems were initiated in relation to RS liquids.
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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
The main conclusions of this study were: 1. Highly size polydisperse liquids are RS in both 2D and 3D. 2. Isomorphs are a good approximation also for (highly) size polydisperse liquids. 3. Melting and freezing rules for size polydisperse liquids can be understood in terms of being RS.
Furthermore, this year, a study of medium range crystalline order (MRCO)in a 2D size polydisperse Lennard-Lones (LJ) liquid was initiated. MRCO has been shown to be relevant for understanding, for instance, supercooled liquids and the glass transition. This study was an ongoing study throughout the year but didn't bring forth any firm conclusions.
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| Strategy for Future Research Activity |
The research projects of the first section were planned to continue into 2015, i.e., the study of MRCO and size polydispersity. Additionally, a study of energy polydisperse LJ liquids was planned for 2015 both in relation to RS liquids and to its novel phase behavior.
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