Updated on 2025/05/08

写真a

 
TAKASHIMA, Chinami
 
Affiliation
Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Assistant Professor(without tenure)
Degree
doctor of science ( 2024.03 Waseda University )
master of science ( 2021.03 Waseda University )
bachelor of science ( 2019.03 Waseda University )
 

Papers

  • Role of picture change correction in relativistic density functional theory: an analogy with coupled cluster theory

    Hiromi Nakai, Chinami Takashima

    Chemistry Letters    2025.04

    　View Summary

    <jats:title>Abstract</jats:title>
    <jats:p>Relativistic density functional theory (RDFT) plays a vital role in electronic structure calculations of heavy-element compounds, where accurate electron density evaluation is essential. We demonstrate that picture change correction (PCC) in RDFT is conceptually analogous to corrections in coupled-cluster theory and that neglecting PCC leads to inconsistencies in electron density evaluation. This work underscores the need to incorporate PCC in RDFT to improve accuracy. Future research should focus on developing computationally efficient schemes to implement PCC without significantly increasing the cost of RDFT calculations.</jats:p>

    DOI

  • Parallelization of Two-Electron Integrals in Spin-Free Infinite-Order Two-Component Hamiltonian

    Chinami Takashima, Hiromi Nakai

    Journal of Chemical Theory and Computation    2025.03

    DOI

  • Evaluation of picture change effects on fractional occupation number states in noble gas atoms

    Chinami Takashima, Hiromi Nakai

    Theoretical Chemistry Accounts    2024.02

    DOI

    Scopus

  • Range Separation Method for Density Functional Theory Based on Two-Electron Infinite-Order Two-Component Hamiltonian

    Chinami Takashima, Hiromi Nakai

    Journal of Chemical Theory and Computation    2024.01

    DOI

    Scopus

  • Theoretical Research on Selective C–H Activation of 8-methylquinoline with Transition Metal Catalysts

    Shuto HOSHINO, Chinami TAKASHIMA, Yuto HORIO, Takanori SHIBATA, Hiromi NAKAI

    Journal of Computer Chemistry, Japan    2024

    DOI

  • Matrix-decomposed two-electron integrals in the infinite-order two-component Hamiltonian

    Chinami Takashima, Hiromi Nakai

    Chemical Physics Letters    2023.10

    DOI

    Scopus

    3
    Citation
    (Scopus)

  • Experimental and Theoretical Evidence for Relativistic Catalytic Activity in C–H Activation of N-Phenylbenzamide Using a Cationic Iridium Complex

    Chinami Takashima, Hisaki Kurita, Hideaki Takano, Yasuhiro Ikabata, Takanori Shibata, Hiromi Nakai

    The Journal of Physical Chemistry A    2022.10

    DOI

    Scopus

    1
    Citation
    (Scopus)

  • Dynamic hetero-metallic bondings visualized by sequential atom imaging

    Minori Inazu, Yuji Akada, Takane Imaoka, Yoko Hayashi, Chinami Takashima, Hiromi Nakai, Kimihisa Yamamoto

    Nature Communications    2022.05

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    <jats:title>Abstract</jats:title><jats:p>Traditionally, chemistry has been developed to obtain thermodynamically stable and isolable compounds such as molecules and solids by chemical reactions. However, recent developments in computational chemistry have placed increased importance on studying the dynamic assembly and disassembly of atoms and molecules formed in situ. This study directly visualizes the formation and dissociation dynamics of labile dimers and trimers at atomic resolution with elemental identification. The video recordings of many homo- and hetero-metallic dimers are carried out by combining scanning transmission electron microscopy (STEM) with elemental identification based on the Z-contrast principle. Even short-lived molecules with low probability of existence such as AuAg, AgCu, and AuAgCu are directly visualized as a result of identifying moving atoms at low electron doses.</jats:p>

    DOI

    Scopus

    11
    Citation
    (Scopus)

  • Photoexcited charge manipulation in conjugated polymers bearing a Ru(<scp>ii</scp>) complex catalyst for visible-light CO2 reduction

    Akinobu Nakada, Ryuichi Miyakawa, Ren Itagaki, Kosaku Kato, Chinami Takashima, Akinori Saeki, Akira Yamakata, Ryu Abe, Hiromi Nakai, HO-CHOL CHANG

    Journal of Materials Chemistry A    2022

    　View Summary

    <jats:p>Photoexcited charge manipulation was demonstrated by molecular engineering in conjugated polymers, bearing a Ru(<jats:sc>ii</jats:sc>) complex as the CO<jats:sub>2</jats:sub> reduction photocatalyst.</jats:p>

    DOI

    Scopus

    7
    Citation
    (Scopus)

  • Database-assisted local unitary transformation method for two-electron integrals in two-component relativistic calculations

    Chinami Takashima, Junji Seino, Hiromi Nakai

    Chemical Physics Letters   777   138691 - 138691  2021.08

    DOI

    Scopus

    5
    Citation
    (Scopus)

  • Implementation of Picture Change Corrected Density Functional Theory Based on Infinite-Order Two-Component Method to GAMESS Program

    Chinami TAKASHIMA, Junji SEINO, Hiromi NAKAI

    Journal of Computer Chemistry, Japan   19 ( 4 ) 128 - 130  2020

    DOI

  • カチオン性イリジウム触媒を用いた均一系触媒反応における相対論効果

    Chinami TAKASHIMA, Yasuhiro IKABATA, Hisaki KURITA, Hideaki TAKANO, Takanori SHIBATA, Hiromi NAKAI

    Journal of Computer Chemistry, Japan   18 ( 3 ) 136 - 138  2019

    DOI

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Internal Special Research Projects

  • 2成分相対論に基づく量子化学計算の並列計算手法の開発と汎用プログラムへの公開

    2024  

    　View Summary

    化学現象を理論的に予測する手法のひとつである量子化学計算では、周期表の高周期に位置する元素を対象とするとき、相対論効果を取り込むことが必須となる。このような相対論的量子化学は膨大な計算コストを必要とするため効率的な計算手法を開発し、実用化することが求められている。本研究では相対論的量子化学のひとつである2成分相対論に基づき、大規模計算機クラスターによる並列計算を実行するための枠組みを開発した。2成分相対論の計算において律速となるのは電子間の相互作用を計算する2電子積分であり、計算時間は分子のサイズNに対してN5、データ量はN4に比例して増加する。そこで理論開発では2電子積分に着目し、電子に属する2つの基底関数の組に基づいて演算を計算機クラスターに割り振るアルゴリズムを開発した。プログラム実装は相対論効果の局所性に基づく線型スケーリング手法である局所ユニタリー変換と組み合わせて行った。また、2電子積分の膨大なデータ保存を回避するdirect SCF法も適用した。プログラムの並列性能は、1次元モデルである直鎖状のアスタチン化水素10量体と3次元モデルである正四面体型の金10量体を用いて検証し、実用に耐えうるパフォーマンスを示すことを確認した。実在系への適用としてプラチナ13核錯体[Pt13(C7H7)6]2+のエネルギー計算を行い、計算時間を計測した。[Pt13(C7H7)6]2+は積分のデータ量の観点から従来のプログラムでは計算が困難であったが、本研究で開発したプログラムによって実用的な計算環境および計算時間で取り扱うことが可能となった。以上の研究成果を原著論文としてJournal of Chemical Theory and Computation に出版した。当該論文はSupplementary Journal Coverに採用された。