| Project/Area Number |
08454105
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物性一般(含基礎論)
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| Research Institution | The University of Tokyo |
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Principal Investigator |
TSUNEYUKI Shinji The University of Tokyo, Institute for Solid State Physics, Associate Professor, 物性研究所, 助教授 (90197749)
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| Co-Investigator(Kenkyū-buntansha) |
KUSAKABE Koichi The University of Tokyo, Institute for Solid State Physics, Research Associate, 物性研究所, 助手 (10262164)
OGITSU Tadashi The University of Tokyo, Institute for Solid State Physics, Research Associate, 物性研究所, 助手 (20262165)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,500,000 (Direct Cost: ¥7,500,000)
Fiscal Year 1997: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1996: ¥6,200,000 (Direct Cost: ¥6,200,000)
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| Keywords | First-Principles Moleculara Dynamics Method / High Pressure / Diamond / BCN Copmound / C60 Polymer / Fullerene / Silicide / SnI_4 / ヘテロダイヤモンド / C_<60>ポリマー / SnI4 / グラファイト / 構造相転移 / 層状物質 |
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| Research Abstract |
High-pressure experiment has playd important role not only in fundamental research of condensed matter physics and geophysics but also in applications for synthesizing metastable crystals inaccessible at ambient pressure. In-situ obsesrvation of a small amount of specimen at ultra high pressure is, however, very difficult in general, so that theoretical suppport by computer simulations is getting morre and more important. This work aim at establishing the method of predicting crystal structures and electronic properties of materials under high pressure independently of experiments by introducing the constant pressure scheme into the traditional formalism of the First-Principles Molecular Dynamics (FPMD) method.
We developed a parallelized computer code of the FPMD method with the conjugate-gradient technique for optimizing electronic structure. We also devised a new method of searching for the transition state of structural transformataion or chemical reaction processes. This computer code has been used for investigation of the following problems :
(1) Comparison of the activation energies for graphite-to-c-diamond and graphite-to-h-diamond structural transformations
(2) Material design of BCN heterodaimond, that is, prediction of the probable structures and their properties, and also proposal of synthesis paths
(3) Structural optimization and large-scale band calculation of alkali-doped C60-polymers
(4) Pressure dependence of the stability of polymorphs of CaSi_2
(5) Search for probable structures of the high-pressurer atomic phase of SnI_4
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