カテゴリー: 未分類

[Published online Journal of Computer Chemistry, Japan Vol.19, 136-138, by J-STAGE]
<Title:> ミクロ相分離構造の最大連結成分と自由エネルギー
<Author(s):> 川口　裕靖, 伊藤　真利子, 山中　貞人, 青柳　岳司, 大西　立顕
<Corresponding author E-Mill:> 20vr029p(at)rikkyo.ac.jp
<Abstract:> In this study, we attempted to quantify the shape of various metastable structures of microphase separation of ABA triblock copolymers that can be observed in a computer simulation. For the quantification, we focused on the domains where the volume fraction of B (or A) is greater than a preset threshold, and defined a measure that indicates how the size of the largest connected component of such domains decreases as the threshold increases. The value of the measure was strongly correlated with the free energy of the metastable structures.
<Keywords:> Block copolymers, Microphase separation, Largest connected component, Metastable structures, Free energy
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/4/19_2021-0001/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 142-145, by J-STAGE]
<Title:> FMOプログラムABINIT-MPの整備状況2020
<Author(s):> 望月　祐志, 坂倉　耕太, 渡邊　啓正, 奥脇　弘次, 加藤　幸一郎, 渡辺　尚貴, 沖山　佳生, 福澤　薫, 中野　達也
<Corresponding author E-Mill:> fullmoon(at)rikkyo.ac.jp
<Abstract:> We have been developing the ABINIT-MP program for fragment molecular orbital (FMO) calculations. In this report, improvements in the latest release Ver. 1 Rev. 22 and demonstrative applications on the Fugaku and ITO supercomputers are summarized.
<Keywords:> Fragment molecular orbital, FMO, ABINIT-MP, Supercomputer
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/4/19_2021-0015/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 149-150, by J-STAGE]
<Title:> アミノ酸間相互作用ポテンシャルにおける光学異性体の影響
<Author(s):> 寺島　千絵子, 谷田　義明, 佐藤　博之
<Corresponding author E-Mill:> c.terashima(at)jp.fujitsu.com
<Abstract:> In order to accelerate the conformational search of peptides, a coarse-grained model in which amino acid residues were treated with an amino acid pair interaction potential was investigated. To treat both natural and artificial types of amino acids and staples, new interaction potentials were developed by umbrella sampling. For the new potential, the effect of optical isomer was investigated with the threonine potential. As a result, the potential of allo-threonine was different from that of L-threonine.
<Keywords:> amino-acid, Peptide, Coarse-grained model, Interaction potential, Molecular dynamics
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/4/19_2021-0006/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 128-130, by J-STAGE]
<Title:> Implementation of Picture Change Corrected Density Functional Theory Based on Infinite-Order Two-Component Method to GAMESS Program
<Author(s):> Chinami TAKASHIMA, Junji SEINO, Hiromi NAKAI
<Corresponding author E-Mill:> nakai(at)waseda.jp
<Abstract:> We implemented the picture change correction method for two-electron Coulomb interaction and density operator, which was based on the infinite-order two-component method with the local unitary transformation, to the GAMESS program. Numerical assessments for molecules containing heavy element confirmed the accuracies and efficiencies of the implementation. Furthermore, the comparison with several types of treatments indicated that whole picture change corrections of one- and two-electron operators and the density operator are necessary for accurate two-component density functional theory calculations.
<Keywords:> Relativistic effect, Infinite-order two-component theory, Local unitary transformation, Picture change, DFT
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/4/19_2021-0002/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 125-127, by J-STAGE]
<Title:> 環状ペプチドの膜透過における溶媒和自由エネルギー計算
<Author(s):> 栁　昂輝, 原田　隆平, 満田　祐樹, 重田　育照
<Corresponding author E-Mill:> shigeta(at)ccs.tsukuba.ac.jp
<Abstract:> The solvation free energies of cyclic dipeptides (CDPs) for a membrane were calculated to evaluate their membrane permeabilities. As a result, there were energy barriers between the membrane center and interface for each CDP. Furthermore, the profiles of solvation free energy depended on the amino acids that construct each CDP. These results indicate that each CDP changes its membrane permeability. Our results will be useful for designing cyclic peptides in the field of medium-molecular-weight drugs.
<Keywords:> MD, Cyclic Dipeptide (CDP), Solvation Free Energy, Energy Representation, Membrane Permeation Process
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/4/19_2021-0008/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 131-132, by J-STAGE]
<Title:> プロトン伝導性PVPA-xIm複合体のプロトン伝導機構の理論的解明
<Author(s):> 堀　太, 末武　鋭也, 井田　朋智, 水野　元博, 重田　育照
<Corresponding author E-Mill:> hori(at)ccs.tsukuba.ac.jp
<Abstract:> This paper overviews the local structures and dynamics of imidazole (Im) in proton-conducting poly (vinylphosphonic acid)-Im (PVPA-xIm) composites investigated by density functional theory calculations and molecular dynamics simulations. These calculations propose the proton conduction mechanism of PVPA-xIm based on Grotthuss-type mechanism consisting the following processes: proton transfers from PVPA to Im and between Im, and the reorientation of Im in the hydrogen-bond Im cluster.
<Keywords:> Imidazole, Proton conduction mechanism, Molecular dynamics simulation, Density functional theory, Grotthuss-type mechanism
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/4/19_2020-0028/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, A12-A18, by J-STAGE]
<Title:> J-PARCミュオン施設 「J-PARC MUSE」
<Author(s):> 三宅　康博
<Abstract:> ミュオン科学実験施設(MUSE)は，中性子, ハドロン, ニュートリノ施設とともに，2001年から2008年にかけて建設が許可されたJ-PARC計画の実験領域の一つである． MUSE施設は物質・生命科学実験施設(MLF)の中にあり，中性子とミュオンの両科学プログラムが統合されている． ミュオン製造用黒鉛ターゲットからパイオンやミュオンを効率的に取り出すための二次ミュオンラインは，Dライン, Uライン, Sライン, Hラインの4つのミュオンビームラインから構成されている．パルスミュオンビームの特徴を生かした10の実験エリア (D1, D2, U1A, U1B, S1, S2, S3, S4, H1, H2)において，様々なミュオン関連の実験を可能にしており，様々なシミュレーションコードを用いて，ビームラインの構成要素の設計を行っている．
<Keywords:> Keywords muon science facility (MUSE), J-PARC, Materials and Life Science Facility (MLF), pions, neutron and muon
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/3/19_2020-0016/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, A6-A11, by J-STAGE]
<Title:> J-PARCミュオンビームで拓く基礎物理実験
<Author(s):> 飯沼　裕美
<Corresponding author E-Mill:> hiromi.iinuma.spin(at)vc.ibaraki.ac.jp
<Abstract:> J-PARC MLF H-Lineとハドロンホール南実験棟で行われている3つの基礎物理実験とその相互関係を紹介します．なぜミュオンが標準模型を超えた新しい物理学へのアプローチに有用なのか，ミュオンのスピンを駆使して初期宇宙の謎を探る方法をご紹介します．
<Keywords:>
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/3/19_2020-0023/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 51-56, by J-STAGE]
<Title:> ミュオン・ミュオニウム化学研究のすすめ
<Author(s):> 高柳　敏幸, 宮崎　貴暉
<Corresponding author E-Mill:> tako(at)mail.saitama-u.ac.jp
<Abstract:> 正または負電荷を有するミュオンを利用すると，ミュオニウム(0.114 amu) およびミュオニックヘリウム(4.11 amu)と呼ばれる軽い水素同位体および重い水素同位体をつくりだすことができる．こうした水素同位体を利用することによって新しい化学研究を展開できる可能性がある．本稿では，これまで行われてきた量子論に基づいたミュオニウム関連分子の理論研究を紹介し，その特異性について解説する．
<Keywords:> Muon, Muonium, Isotope effect, Nuclear quantum effect
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/3/19_2020-0009/_article/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.19, 57-63, by J-STAGE]
<Title:> Antiferromagnetic Orderings of Alkali-metal Nanoclusters Arrayed in Sodalite Crystal Studied by μSR and Other Microscopic Probes
<Author(s):> Takehito NAKANO
<Corresponding author E-Mill:> takehito.nakano.phys(at)vc.ibaraki.ac.jp
<Abstract:> Abstract: Alkali metal clusters with an unpaired electron can be periodically arranged in a body-centered cubic structure in sodalite, a type of aluminosilicate zeolite, to form a Mott insulator accompanied with an antiferromagnetic ordering. This system does not contain any magnetic elements and is a novel magnetic system in which the magnetic order is realized by alkali metal s-electrons. In order to investigate the origin of the s-electron magnetism in detail, we present examples of studies using muon spin rotation/relaxation (μSR), synchrotron radiation M ssbauer spectroscopy, and neutron diffraction techniques. The spatial expansion of the s-electron wave functions of the nanoclusters with increasing alkali metal content has been directly observed by these experimental methods. This enhances the exchange interaction and increases the transition temperature (N el temperature). A very simple model material of the Mott-Hubbard system is realized in s-electrons. We also point out that there are great expectations for the future contribution of computer science to this material system, especially to μSR experiments.
<Keywords:> Alkali-metal cluster, Zeolite, Sodalite, Antiferromagnetism, Mott insulator, Muon spin rotation/relaxation, Synchrotron radiation M ssbauer spectroscopy, Neutron diffraction
<URL:> https://www.jstage.jst.go.jp/article/jccj/19/3/19_2020-0020/_article/-char/ja/