发布求助
文献互助 智能选刊 最新文献

Soft Computing Letters最新文献

筛选
英文 中文
The Dipole Polarizability of Uracil in Aqueous Solution. A Sequential Monte Carlo/Quantum Mechanics Study 尿嘧啶在水溶液中的偶极极化性。时序蒙特卡罗/量子力学研究
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913138
V. Ludwig, S. Canuto
{"title":"The Dipole Polarizability of Uracil in Aqueous Solution. A Sequential Monte Carlo/Quantum Mechanics Study","authors":"V. Ludwig, S. Canuto","doi":"10.1163/157404007782913138","DOIUrl":"https://doi.org/10.1163/157404007782913138","url":null,"abstract":"A combined and sequential Monte Carlo/quantum mechanics methodology is used to estimate the dipole polarizability of uracil in aqueous solution in normal thermodynamic conditions. Using the structures generated by the MC simulation, statistically uncorrelated configurations are sampled for subsequent quantum mechanical calculations using the central uracil molecule surrounded by the first solvation shell composed of 26 explicit water molecules. The dipole polarizability is obtained as an average value obtained from density-functional-theory calculations, using the B3P86 functional with varying basis sets. Statistically convergent result for the dipole polarizability of uracil in aqueous solution gives the average value of 100.1 ± 10.4 a03, indicating an increase of about 50% compared to the gas phase result.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"1 1","pages":"215-222"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82336595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Parallelization Efficiency of the Elongation Method and its Application to NLO Design for Urea Crystal 延伸法并行化效率及其在尿素晶体NLO设计中的应用
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913363
K. Naka, F. Gu, Y. Aoki, S. Ohnishi
{"title":"Parallelization Efficiency of the Elongation Method and its Application to NLO Design for Urea Crystal","authors":"K. Naka, F. Gu, Y. Aoki, S. Ohnishi","doi":"10.1163/157404007782913363","DOIUrl":"https://doi.org/10.1163/157404007782913363","url":null,"abstract":"The elongation method designed for calculating the electronic structures of aperiodic polymers has been investigated in parallelization efficiency. The elongation finite-field method for determining (hypper)polarizabilities has been successfully applied to the three-dimensional urea crystal and its derivatives. It is shown that the elongation-FF method is suitable to large-scale calculations with parallelization and a powerful tool for nonlinear optical material designing.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"64 1","pages":"231-241"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80991993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Removing the extra frontier parameters in QM/MM methods: a tentative with the Local Self-Consistent Field method 去除QM/MM方法中额外边界参数:局部自洽场方法的尝试
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913309
Pierre‐François Loos, A. Fornili, M. Sironi, X. Assfeld
{"title":"Removing the extra frontier parameters in QM/MM methods: a tentative with the Local Self-Consistent Field method","authors":"Pierre‐François Loos, A. Fornili, M. Sironi, X. Assfeld","doi":"10.1163/157404007782913309","DOIUrl":"https://doi.org/10.1163/157404007782913309","url":null,"abstract":"We present a new quantum mechanics/molecular mechanics (QM/MM) scheme based on the Local-SCF method that avoids the extra-parametrization of the QM/MM frontier by taking into account the core electrons of the hybrid frontier atoms by means of self-consistent core orbitals (SCCO). This study follows and extends our previous investigation based on frozen core orbitals (FCO) [Chem. Phys. Lett. 427 236-240(2006)]. Test calculations on small organic compounds show that the most common atoms found in biochemical systems can be used as frontier atoms without adding any parameters, and that only relatively small geometric and energetic deviations compared to full-QM calculations are generated.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"86 1","pages":"473-486"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84123149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Ab Initio Studies of the Dipole Moments and Polarizabilities of p-nitroaniline and Related Molecules in their Ground and Excited States. 对硝基苯胺及其相关分子基态和激发态偶极矩和极化率的从头算研究。
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913255
A. Hinchliffe, Mohamed Efhil, H. Soscún
{"title":"Ab Initio Studies of the Dipole Moments and Polarizabilities of p-nitroaniline and Related Molecules in their Ground and Excited States.","authors":"A. Hinchliffe, Mohamed Efhil, H. Soscún","doi":"10.1163/157404007782913255","DOIUrl":"https://doi.org/10.1163/157404007782913255","url":null,"abstract":"We report Ab Initio energies, dipole moments and mean dipole polarizabilities for the ground and five lowest electronic excited singlet states of nitromethane, methylamine, nitromethylamine, nitrobenzene, aniline and p-nitroaniline, together with ground state data for methane and benzene. Ground state properties were calculated using the HF/6-311++G(2d,1p) model whilst excited states were modelled using CIS and CIS(D). Our ground state results are consistent with available experimental data and other advanced literature calculations. The XCH2Y calculations give group contributions of 13.6 atomic units (au) for NO2 and 7.7 au for NH2. The XC6H4Y 's suggest 14.4 and 10.8 au, but there is no evidence of a contribution from the push-pull mechanism. The excited state dipole moments and 's are consistent with the sparse experimental data, and we predict immensely enhanced values for these properties in many of the excited states.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"41 1","pages":"243-249"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73276416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Evaluation of NMR Chemical Shift by Fragment Molecular Orbital Method 用片段分子轨道法评价核磁共振化学位移
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913390
H. Sekino, N. Matsumura, Y. Sengoku
{"title":"Evaluation of NMR Chemical Shift by Fragment Molecular Orbital Method","authors":"H. Sekino, N. Matsumura, Y. Sengoku","doi":"10.1163/157404007782913390","DOIUrl":"https://doi.org/10.1163/157404007782913390","url":null,"abstract":"NMR chemical shifts are evaluated by the Fragment Molecular Orbital (FMO) method. Several practical approximations for the method are tested for water oligomer and poly-chloroprene. The FMO method reproduces the value by the ab-initio method without approximation and the experimental values. The adjacent approximation in fragment pair correction is found to be useful for qualitative prediction of NMR chemical shift in large bio-molecular systems, while monomer approximation fails in predicting the shielding constants of nuclei especially near the division for fragmentation. Preliminary application of the method with low level basis set to a bio-molecule indicates encouraging results for using the method as a theoretical tool in molecular biology.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"9 1","pages":"423-430"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77120778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 12
First-Principles Langevin Molecular Dynamics Studies of Metallic and Semiconductor Clusters: GGA versus LDA Results 金属和半导体团簇的第一性原理Langevin分子动力学研究:GGA与LDA结果
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913273
L. Balbás
{"title":"First-Principles Langevin Molecular Dynamics Studies of Metallic and Semiconductor Clusters: GGA versus LDA Results","authors":"L. Balbás","doi":"10.1163/157404007782913273","DOIUrl":"https://doi.org/10.1163/157404007782913273","url":null,"abstract":"The combination of Langevin molecular dynamics for simulated annealing with realistic quantum-mechanical interactions obtained from first principles supercell calculations within the pseudo potential plane-wave method are applied to examine the structural and electronic properties of the following systems i) pure and mixed GenTem (n, m = 0 - 2), Ge3, Te3 and Ge3Te3 semiconductor clusters, and ii) bimetallic PbNan (n ≤ 7) clusters. Results using the local density approximation (LDA) and the generalized gradient approximation (GGA) for the exchange correlation functional are compared with available experimental data. It is found that the GGA leads to larger bond lengths and smaller binding energies than the LDA, but both approximations lead to the same group symmetry for the ground state of these clusters. Two isomeric configurations for PbNa6, having C3v and Oh symmetries, respectively, are found. The dipole moments of semiconductor clusters are compared with those estimated from recent experiments at room temperature. The dipole moments from GGA calculations are, on average, in better agreement with experiments than those calculated with the LDA.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"3 1","pages":"163-174"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78953415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Hartree-Fock limit values of multipole moments, polarizabilities and hyperpolarizabilities for atoms and diatomic molecules 原子和双原子分子的多极矩、极化率和超极化率的Hartree-Fock极限值
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913408
J. Kobus
{"title":"Hartree-Fock limit values of multipole moments, polarizabilities and hyperpolarizabilities for atoms and diatomic molecules","authors":"J. Kobus","doi":"10.1163/157404007782913408","DOIUrl":"https://doi.org/10.1163/157404007782913408","url":null,"abstract":"This article presents the numerical, finite difference, Hartree-Fock method as a source of reference values of total energies, multipole moments, static polarizabilities and hyperpolarizabilities (αzz, βzzz, γzzzz, Az,zz and Bzz,zz) for atoms and diatomic molecules. The finite field method is used to evaluate polarizabilities and hyperpolarizabilities as derivatives of the dipole and quadrupole moments with respect to the field. The finite difference calculations are compared with other numerical and finite basis set results. Since the finite difference Hartree-Fock method is capable of producing multipole moments with 10-12 significant figure accuracy the high quality of (hyper)polarizability values can be guaranteed.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"19 1","pages":"71-113"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87400267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 13
Response Properties of 2-Electron 2-D Quantum Dots: Triplet Versus Singlet. 二电子二维量子点的响应特性:三重态与单重态。
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913444
M. Ghosh, K. Hazra, S. Bhattacharyya
{"title":"Response Properties of 2-Electron 2-D Quantum Dots: Triplet Versus Singlet.","authors":"M. Ghosh, K. Hazra, S. Bhattacharyya","doi":"10.1163/157404007782913444","DOIUrl":"https://doi.org/10.1163/157404007782913444","url":null,"abstract":"The linear and non-linear optical response properties of 2-D quantum dots with two interacting carrier electrons having triplet coupling of spins are computed and compared with their singlet counterparts. The significant dependence of the response properties on the spin multiplicity in the high and low field regimes are sought to be rationalized.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"78 1","pages":"183-191"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83931493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Theoretical Study on the Polarizabilities of Molecules in Solution by the Quantum Mechanical/Molecular Mechanical Approach: Comparison with the Polarizable Continuum Model 用量子力学/分子力学方法研究溶液中分子极化的理论研究:与可极化连续体模型的比较
Soft Computing Letters Pub Date : 2007-11-01 DOI: 10.1163/157404007782913453
Hideaki Takahashi, M. Kitaura, R. Kishi, Suguru Ohta, Rika Okaji, S. Furukawa, M. Nakano
{"title":"Theoretical Study on the Polarizabilities of Molecules in Solution by the Quantum Mechanical/Molecular Mechanical Approach: Comparison with the Polarizable Continuum Model","authors":"Hideaki Takahashi, M. Kitaura, R. Kishi, Suguru Ohta, Rika Okaji, S. Furukawa, M. Nakano","doi":"10.1163/157404007782913453","DOIUrl":"https://doi.org/10.1163/157404007782913453","url":null,"abstract":"We compute the static polarizabilities of formaldehyde and ethylene in water solution by means of the QM/MM simulations and the polarizable continuum model for the purpose to examine the dependence of the polarizability on the method to include solvent effects. It is found that the polarizability of formaldehyde as well as ethylene is hardly changed by the solvent modeled by QM/MM approach. The results are reasonably consistent with suggestions given by other theoretical investigations which revealed that polarizabilities of a monomer in the linear hydrogen bonded chain is not increased by the hydrogen bondings. In contrast to the QM/MM method, it turns out that the polarizabilities are clearly enhanced for the solutes embedded in the dielectric continuums though both methods indicate that the σ electrons dominantly contribute to the polarizability.","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"72 1","pages":"441-448"},"PeriodicalIF":0.0,"publicationDate":"2007-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83207378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Quantum Chemical DFT and Spectroscopic UV-Vis-NIR Analysis of a Series of Push-Pull Oligothiophenes End-Capped by Amino/Cyanovinyl Groups 氨基/氰乙烯基端封的一系列推拉型寡硫吩的量子化学DFT和紫外-可见-近红外光谱分析
Soft Computing Letters Pub Date : 2007-03-06 DOI: 10.1163/157404007779994214
M. M. Oliva, M. R. Delgado, J. Casado, M. Raposo, A. Fonseca, H. Hartmann, V. Hernández, J. Navarrete
{"title":"Quantum Chemical DFT and Spectroscopic UV-Vis-NIR Analysis of a Series of Push-Pull Oligothiophenes End-Capped by Amino/Cyanovinyl Groups","authors":"M. M. Oliva, M. R. Delgado, J. Casado, M. Raposo, A. Fonseca, H. Hartmann, V. Hernández, J. Navarrete","doi":"10.1163/157404007779994214","DOIUrl":"https://doi.org/10.1163/157404007779994214","url":null,"abstract":"A series of push-pull chromophores built around thiophene-based π-conjugating spacers and bearing various types of amino-donors and cyanovinyl-acceptors have been analyzed by means of UV-Vis-NIR spectroscopic measurements. Density functional theory (DFT) calculations have also been performed to help the assignment of the most relevant electronic features and to derive useful information about the molecular structure of these NLO-phores. The effects of the donor/acceptor substitution in the electronic and molecular properties of the π -conjugated spacer have been addressed. The effectiveness of the intramolecular charge transfer (ICT) has also been tested as a function of the nature of the end groups (i.e., electron-donating or electron-withdrawing capabilities).","PeriodicalId":101169,"journal":{"name":"Soft Computing Letters","volume":"8 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2007-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85159944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信