実験と計算によるイルソグラジン マレイン酸の結晶構造の予測 [Published online J. Comput. Chem. Jpn., 18, 156-158, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 156-158, by J-STAGE]
<Title:> 実験と計算によるイルソグラジン マレイン酸の結晶構造の予測
<Author(s):> 坂田 千夏, 岡本 有史, 梅田 大貴, 古石 誉之, 福澤 薫, 米持 悦生
<Corresponding author E-Mill:> k-fukuzawa(at)hoshi.ac.jp
<Abstract:> To improve the solubility of poorly water-soluble drugs, molecular complexes such as co-crystals and salts have been used. However, the huge number of combinations of drug substances and co-crystal former (coformer) makes experimental screening too expensive. In this study, with the subject of irsogladine maleate [1] whose crystal structure has already been reported, we investigated the predictability of the crystal structure using the computational method. In the experiment on irsogladine-maleic acid complex, single crystal X-ray structural analysis, powder X-ray diffraction (PXRD) method, and Fourier transform infrared spectroscopy (FT-IR) measurement have already been performed; lattice constant and interaction site were known and it is known to be a salt crystal. We used CONFLEX software and MMFF94S force field parameters for crystal structure prediction. As a result, it was possible to obtain a crystal structure consistent with the experimental structure.
<Keywords:> Crystal structure prediction, Salt crystal, Irsogladine maleate, Physical property improvement, CONFLEX
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0024/_article/-char/ja/

分子動力学法によるSN2反応の理論研究ー化学反応はいかにして起こるかー [Published online J. Comput. Chem. Jpn., 18, 145-146, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 145-146, by J-STAGE]
<Title:> 分子動力学法によるSN2反応の理論研究ー化学反応はいかにして起こるかー
<Author(s):> 松原 世明
<Corresponding author E-Mill:> matsubara(at)kanagawa-u.ac.jp
<Abstract:>
<Keywords:> S??sub??N??/sub??2 reaction, Molecular dynamics simulation, Requirement for the reaction, Solvent effect
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0011/_article/-char/ja/

ペロブスカイト太陽電池材料におけるポーラロン形成の量子力学的分子動力学シミュレーション [Published online J. Comput. Chem. Jpn., 18, 142-144, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 142-144, by J-STAGE]
<Title:> ペロブスカイト太陽電池材料におけるポーラロン形成の量子力学的分子動力学シミュレーション
<Author(s):> 浦谷 浩輝, 周 建斌, 中井 浩巳
<Corresponding author E-Mill:> nakai(at)waseda.jp
<Abstract:> Polarons, which are charge carriers in solids wearing a structural deformation, play a key role in photo-electronic devices such as solar cells. In this study, the polaron formation process in a lead halide perovskite, which is utilized in perovskite solar cells, was simulated using quantum mechanical molecular dynamics calculations. The simulations were performed in a several nanometers-scale model system to capture the spatial size of the polarons, with the use of the divide-and-conquer type density-functional tight-binding method, which is capable of fully quantum mechanical treatment of systems consisting of (tens of) thousands of atoms. The observed structural deformations and their process are discussed.
<Keywords:> Polaron, Perovskite solar cell, Divide-and-conquer method, Density-functional tight-binding method, Quantum mechanical molecular dynamics simulation
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0025/_article/-char/ja/

シクロフェニレン骨格での置換基の電子伝達機構 [Published online J. Comput. Chem. Jpn., 18, 147-149, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 147-149, by J-STAGE]
<Title:> シクロフェニレン骨格での置換基の電子伝達機構
<Author(s):> 亮治 藤山, あゆみ 井上, 夢月 原田
<Corresponding author E-Mill:> fujiyama(at)kochi-u.ac.jp
<Abstract:> In order to examine the transmision of electronic effects in cyclophenylene framework, substituent effects on some cyclophenylene derivatives with primary carbocation CH2+ were carried out. The substituent effects on the energy of isodesmic reactions were analyzed by the LSFE equation that separates the inductive and the resonance effects . The analysis results indicate that the counterclockwise and the clockwise resonances shown in the Figure are mainly important.
<Keywords:> Cyclophenylene, Substituent effect, LSFE equation, Resonance effect, Biphenylene
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0018/_article/-char/ja/

相対論的量子化学計算プログラムRAQETの公開 [Published online J. Comput. Chem. Jpn., 18, A6-A11, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, A6-A11, by J-STAGE]
<Title:> 相対論的量子化学計算プログラムRAQETの公開
<Author(s):> 五十幡 康弘, 吉川 武司, 中井 浩巳
<Corresponding author E-Mill:> nakai(at)waseda.jp
<Abstract:> The “Relativistic And Quantum Electronic Theory (RAQET)” program was released for academic use. One-component (spin-free) and two-component (spin-dependent) relativistic calculations are possible based on the infinite-order Douglas-Kroll-Hess transformation and local unitary transformation. This review describes available features, registration/installation, and input/output of the RAQET program.
<Keywords:>
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0022/_article/-char/ja/

機械学習によるテキスト処理ツールの開発と応用 [Published online J. Comput. Chem. Jpn., 18, 123-125, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 123-125, by J-STAGE]
<Title:> 機械学習によるテキスト処理ツールの開発と応用
<Author(s):> 亘理 結香, 奥脇 弘次, 望月 祐志
<Corresponding author E-Mill:> fullmoon(at)rikkyo.ac.jp
<Abstract:> We have developed a text processing tool consisting of several machine learning-related programs such as TreeTagger and Doc2Vec. This system was applied to a number of abstracts of a couple of physical chemistry journals (Chemical Physics Letters and American Journal of Physics). The degree of similarity of contents was then made evaluatable as a guide for papers to be checked for a certain topic.
<Keywords:> Text processing, Machine learning, Doc2Vec, Degree of similarity
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0012/_article/-char/ja/

ABINIT-MP Openシリーズの最新の開発状況について [Published online J. Comput. Chem. Jpn., 18, 129-131, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 129-131, by J-STAGE]
<Title:> ABINIT-MP Openシリーズの最新の開発状況について
<Author(s):> 望月 祐志, 秋永 宜伸, 坂倉 耕太, 渡邊 啓正, 加藤 幸一郎, 渡辺 尚貴, 奥脇 弘次, 中野 達也, 福澤 薫
<Corresponding author E-Mill:> fullmoon(at)rikkyo.ac.jp
<Abstract:> We have been developing an original program named ABINIT-MP for fragment molecular orbital (FMO) calculations. Various functionalities for interaction analyses, e.g. PIEDA (Pair Interaction Energy Decomposition Analysis), have been augmented in Revision 10 and Revision 15 of the ABINIT-MP Open Series Version 1. In this Letter, we briefly describe such new features.
<Keywords:> キーワード:Fragment molecular orbital, FMO, ABINIT-MP, Interaction analysis, Correlation energy correction
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0016/_article/-char/ja/

Scratchを経由する機械学習教材の開発の試み [Published online J. Comput. Chem. Jpn., 18, 126-128, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 126-128, by J-STAGE]
<Title:> Scratchを経由する機械学習教材の開発の試み
<Author(s):> 満野 仁美, 奥脇 弘次, 伊藤 雅仁, 望月 祐志
<Corresponding author E-Mill:> fullmoon(at)rikkyo.ac.jp
<Abstract:> We have been developing a Scratch-based educational program for machine learning in the chemistry context. This system has an interface with the DeepChem library set of Python. The solubility prediction of several molecules with SMILES notation was demonstrated as a preliminary application.
<Keywords:> キーワード:Scratch, Educational program, Machine learning, DeepChem, Solubility prediction
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0013/_article/-char/ja/

転移学習と生成ネットワークの試行事例 [Published online J. Comput. Chem. Jpn., 18, 132-135, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 132-135, by J-STAGE]
<Title:> 転移学習と生成ネットワークの試行事例
<Author(s):> 伊藤 雅仁, 篠嶋 友也, 望月 祐志, 秋永 宜伸, 小杉 範仁
<Corresponding author E-Mill:> fullmoon(at)rikkyo.ac.jp
<Abstract:> Transfer learning has attracted interests because of the reduction of training costs. We applied this technique to the analyses for visualized results of computational fluid dynamics (CFD) simulations on 2-dimensional wing models. The accuracy and cost reduction were addressed. Preliminary studies of generative network have been made as well.
<Keywords:> Transfer learning, Generative network, Keras, 2-dimensional wing model, Computational fluid dynamics
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0023/_article/-char/ja/

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 [Published online J. Comput. Chem. Jpn., 18, 136-138, by J-STAGE]

[Published online Journal of Computer Chemistry, Japan Vol.18, 136-138, by J-STAGE]
<Title:> 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
<Author(s):> 髙島 千波, 五十幡 康弘, 栗田 久樹, 高野 秀明, 柴田 高範, 中井 浩巳
<Corresponding author E-Mill:> nakai(at)waseda.jp
<Abstract:> A cationic Ir complex was reported to show specific catalytic activity in C-H bond activation reaction of benzanilides. The present study examined reaction energy profiles of the C-H bond activation with Ir and Rh catalysts based on non-relativistic and relativistic quantum chemical calculations. We found that the relativistic effect is essential to demonstrate the difference in the catalytic activity. In particular, the activation of the d orbital of Ir, which is caused by the s- and p- orbital contraction followed by the self-consistent d-orbital expansion, leads to stabilization of the transition state and product of the C-H bond activation.
<Keywords:> C-H Bond activation, Transition metal catalyst, Relativistic effect, Oxidative addition, Iridium
<URL:> https://www.jstage.jst.go.jp/article/jccj/18/3/18_2019-0021/_article/-char/ja/