月別: 2018年2月

[Published online Journal of Computer Chemistry, Japan Vol.16, 147-148, by J-STAGE]
<Title:> メタン活性化を目指したインフォマティクス
<Author(s):> 蒲池　高志, 斎藤　雅史, 辻　雄太, 吉澤　一成
<Corresponding author E-Mill:> kamachi(at)fit.ac.jp
<Abstract:> We investigated the C H bond cleavage of methane on various binary alloys using periodic density functional theory (DFT) calculations for catalyst screening. Cohesive energy, which strongly correlates with activation energy and heat of reaction for the C H bond cleavage, was computed for 337 alloys in AFLOW database to enable rapid screening.
<Keywords:> メタン転換触媒, 密度汎関数法, 触媒インフォマティクス
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0058/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 149-151, by J-STAGE]
<Title:> III-V族ヘテロ6員環からなるGaPおよびGaNナノ構造体の分子構造と電子構造
<Author(s):> 小路　謙介, 松永　雄樹, 武田　京三郎
<Corresponding author E-Mill:> takeda(at)waseda.jp
<Abstract:> We computationally design GaN and GaP heteroatom nanostructures of nanoribbons (NRBs), nanorings (NRGs), and nanotubes (NTBs), and study the atomistic and electronic structures theoretically. First-principles calculations demonstrate that GaN finite NRBs have a flat molecular plane whereas GaP NRBs break the flatness of the NRB molecular planes. Although an NRG is produced by rolling an NRB (head to tail), the GaP system produces a specific NRG having a “magic ring numbe” whereas the GaN system can freely change the NRG diameter. A NTB stacked by these NRGs has a potential to be a one-dimensional semiconductor having a band gap of 1.5 3 eV and effective mass ratios 0.3 1.7 eV for an electron and a hole.
<Keywords:> GaN, GaP, NRB, NRG, NTB, Electronic and Molecular Structures, First-principles calculation
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0060/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 139-140, by J-STAGE]
<Title:> Isospectral Tree Graph を生み出すdormantの発見(II)
<Author(s):> 細矢　治夫
<Corresponding author E-Mill:> hosoya.haruo(at)ocha.ac.jp
<Abstract:> Although not completed yet, mathematical foundation for the existence and algorithm of finding the dormant tree graphs is being pursued.
<Keywords:> Isospectral tree graph, Characteristic polynomial, Topological index, Hosoya index, Zindex, Z-counting polynomial, Dormant, Sprout
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0070/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 135-138, by J-STAGE]
<Title:> First Principles Evolutionary Search for New Electrides along the Dimensionality of Anionic Electrons
<Author(s):> Tomofumi TADA, Junjie WANG, Hideo HOSONO
<Corresponding author E-Mill:> tada.t.ae(at)m.titech.ac.jpJanuary
<Abstract:> We propose a unique strategy based on the dimensionality of anionic electrons for new inorganic electride search. We adopted strontium phosphide as the initiator for the evolutionary search, and our evolutionary calculations combined with experimental synthesis found the Sr₅P₃ is a new one-dimensional electride.
<Keywords:> Electride, Evolutionary search, First principles.
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0067/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 144-146, by J-STAGE]
<Title:> フタロシアニン類—フラーレンC₆₀間の距離依存による電子状態の変化
<Author(s):> 池永　祐乙, 成島　和男, 光井　和輝
<Corresponding author E-Mill:> narushim(at)ube-k.ac.jp
<Abstract:> Recently, renewable energy is attracting attention globally. In Japan today, there is a shift with growing momentum to photovoltaic power generation from thermal power generation, which has heretofore served as the foundation of electrical power generation. We are studying improvement of the photovoltaic conversion efficiency of bulk heterojunction organic thin film solar cells and are preparing a device that requires detailed elucidation of its electronic properties and its mechanism of power generation. Accordingly, we have conducted quantum chemical calculations using a molecular pair of phthalocyanine and fullerene C₆₀ employed as a specimen. Specifically, we have computed charge densities and electron clouds in the ground state while varying the molecular distance to 12 and 24 using the density functional method. Results demonstrate quite high negative charge density in C atoms near phthalocyanine in C₆₀ when the distance between the two molecules is decreased to 12 , with a positive charge density in C atoms on the opposite side of phthalocyanine in C₆₀. Results suggest that many conduction electrons and positive holes, the so-called carriers, are generated in the phthalocyanine – fullerene C₆₀ bimolecular system when the molecular distance is decreased to 12 .
<Keywords:> キーワード：Bulk Hetero Junction, Phthalocyanine, Fullerene, Density Functional Theory, Charge Density
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0064/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 141-143, by J-STAGE]
<Title:> ナイロン6様分子をフタロシアニン類に混入した系における電子状態の考察
<Author(s):> 成島　和男, 池永　祐乙, 光井　和輝
<Corresponding author E-Mill:> narushim(at)ube-k.ac.jp
<Abstract:> Since the appearance of bulk heterostructures, organic thin film solar cells have attracted attention as next-generation energy sources. Earlier studies have addressed quantum chemical calculation in an excited state and a ground state of phthalocyanine fullerene bimolecular systems. Phthalocyanines and fullerenes are well known as materials of organic thin film solar cells. Based on these reports, we have devised a new method of manufacturing organic thin film solar cells and have prepared a device incorporating those features. Nevertheless, the device is so soft that it is considered necessary to strengthen the device by incorporating a fibrous substance. This study investigated the effects on its electronic properties of incorporating molecules like nylon 6 into phthalocyanine using quantum chemical calculation. Results demonstrate partial defects in the electron cloud of phthalocyanine molecules, revealing the occurrence of positive holes. These electron cloud defects result from interaction between nylon dimer molecules and phthalocyanine molecules.
<Keywords:> キーワード：Organic thin Film Solar Cell, Molecular Orbital Method, Phthalocyanine, Nylon 6, Charge Density
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0063/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 129-130, by J-STAGE]
<Title:> 計算機化学を用いたムライト結晶の構造異常の研究
<Author(s):> 鈴木　泰地, 長島　啓, 中嶋　義晴, 内田　希
<Corresponding author E-Mill:> s153242(at)stn.nagaokaut.ac.jp
<Abstract:> Mullite has a complicated crystal structure in which double occupancy of metal atoms and oxygen vacancies take a random arrangement．Various attempts have been made to describe its structure，but it has not yet been fully described．The purpose of this study is to clarify that the random arrangement has regularity. Excluding arbitrariness，the arrangement of metal atoms and oxygen vacancies of mullite crystals of three compositions (1.58Al₂O₃，1.75Al₂O₃，1.95Al₂O₃ for 1SiO₂) was randomly generated．Structural relaxation calculations of these models were performed，and their stability was examined．The wide distribution of the heat of formation obtained by the structural relaxation calculation was consistent with the composition．
<Keywords:> mullite, crystal structure, structural relaxation calculation, excluding arbitrariness, random arrangement
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0057/_html/-char/ja/

[Advanced Published online Journal of Computer Chemistry, Japan, by J-STAGE]
<Title:> フラグメント分子軌道(FMO)法を用いた散逸粒子動力学シミュレーションのための有効相互作用パラメータ算出の自動化フレームワーク
<Author(s):> 奥脇　弘次, 土居　英男, 望月　祐志
<Corresponding author E-Mill:> okuwaki(at)rikkyo.ac.jp
<Abstract:> 近年，用途に応じて目的の機能を有した材料開発の要求が高まっており，大規模な構造予測のためのシミュレーションが注目を浴びている．私達は，今回，散逸 粒子動力学(DPD: Dissipative Particle Dynamics)シミュレーションを例に，有効相互作用パラメータ(χパラメータと呼ばれる) をフラグメント分子軌道(FMO)法から算定するためのフレームワークとワークフローシステムを開発した．FMO計算は非経験的であるため，高分子系素材 に関わるほとんどの有機化合物に対して使うことが可能であり，χパラメータの算定に対して汎用性を持つと考えられる．この報告では，本システム (FCEWS: FMO-based Chi-parameter Evaluation Workflow System)の開発の目的，理論的な背景，ならびにソフトウェアについて解説する．
<Keywords:> Dissipative particle dynamics, DPD, fragment molecular orbital, FMO, chi-parameter
<URL:> https://www.jstage.jst.go.jp/article/jccj/advpub/0/advpub_2017-0048/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 133-134, by J-STAGE]
<Title:> 原子価結合局在電子波束による分子内電子励起ダイナミクス
<Author(s):> 安藤　耕司
<Corresponding author E-Mill:> ando_k(at)lab.twcu.ac.jp
<Abstract:> A simple model of localized electron wave packets, floating and breathing Gaussians with non-orthogonal valence-bond spin-coupling, is demonstrated to produce an accurate high-harmonic generation (HHG) spectrum from an LiH molecule induced by an intense laser pulse. In contrast with the conventional molecular orbital picture in which the Li 2s and H 1s atomic orbitals are strongly mixed in the valence σ bonding orbital, the present calculation indicates that a superposition of independent responses of the electrons reproduces the spectrum in which the contribution of the H 1s electron dominates the characteristic plateau and cut-off of HHG.
<Keywords:> Electron dynamics, Localized wave-packets, Valence-bond theory, High-harmonic generation
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0056/_html/-char/ja/

[Published online Journal of Computer Chemistry, Japan Vol.16, 131-132, by J-STAGE]
<Title:> 計算化学手法によるフラーレンの位置選択的反応の解析
<Author(s):> 伊熊　直彦
<Corresponding author E-Mill:> ikuma(at)chem.eng.osaka-u.ac.jp
<Abstract:> Organic reactions with fullerene realize functional nanomaterials, although selective functionalization is still challenging because of many equivalent olefins causing various regioisomers. Thus, the improvement of reactivity and regioselectivity of C₆₀ reaction has been realized by structural organic chemistry such as enhancement of strain, introduction of heteroatom, and nucleophilic additoin via single eletron transfer (Figure 1 Figure 1. Concept of the activation of C₆₀ to obtain regioselective adducts. ). This paper presents the theoretical clarification for the reactivity and selectivity of these activated reaction conditions.
<Keywords:> Fullerene, Regioselectivity, Strain energy, Ambident basicity, Single elecron transfer
<URL:> https://www.jstage.jst.go.jp/article/jccj/16/5/16_2017-0054/_html/-char/ja/