arXiv - PHYS - Chemical Physics最新文献_第9页

Highly Accurate Real-space Electron Densities with Neural Networks 利用神经网络实现高精度实空间电子密度

arXiv - PHYS - Chemical Physics Pub Date : 2024-09-02 DOI: arxiv-2409.01306

Lixue Cheng, P. Bernát Szabó, Zeno Schätzle, Derk Kooi, Jonas Köhler, Klaas J. H. Giesbertz, Frank Noé, Jan Hermann, Paola Gori-Giorgi, Adam Foster

{"title":"Highly Accurate Real-space Electron Densities with Neural Networks","authors":"Lixue Cheng, P. Bernát Szabó, Zeno Schätzle, Derk Kooi, Jonas Köhler, Klaas J. H. Giesbertz, Frank Noé, Jan Hermann, Paola Gori-Giorgi, Adam Foster","doi":"arxiv-2409.01306","DOIUrl":"https://doi.org/arxiv-2409.01306","url":null,"abstract":"Variational ab-initio methods in quantum chemistry stand out among other\u0000methods in providing direct access to the wave function. This allows in\u0000principle straightforward extraction of any other observable of interest,\u0000besides the energy, but in practice this extraction is often technically\u0000difficult and computationally impractical. Here, we consider the electron\u0000density as a central observable in quantum chemistry and introduce a novel\u0000method to obtain accurate densities from real-space many-electron wave\u0000functions by representing the density with a neural network that captures known\u0000asymptotic properties and is trained from the wave function by score matching\u0000and noise-contrastive estimation. We use variational quantum Monte Carlo with\u0000deep-learning ans\"atze (deep QMC) to obtain highly accurate wave functions\u0000free of basis set errors, and from them, using our novel method,\u0000correspondingly accurate electron densities, which we demonstrate by\u0000calculating dipole moments, nuclear forces, contact densities, and other\u0000density-based properties.","PeriodicalId":501304,"journal":{"name":"arXiv - PHYS - Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190209","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

Quantum Density Mechanics: Accurate, purely density-based textit{ab initio} implementation of many-electron quantum mechanics 量子密度力学：精确、纯粹基于密度的多电子量子力学（textit{ab initio}）实现

arXiv - PHYS - Chemical Physics Pub Date : 2024-09-01 DOI: arxiv-2409.00586

James C. Ellenbogen

{"title":"Quantum Density Mechanics: Accurate, purely density-based textit{ab initio} implementation of many-electron quantum mechanics","authors":"James C. Ellenbogen","doi":"arxiv-2409.00586","DOIUrl":"https://doi.org/arxiv-2409.00586","url":null,"abstract":"This paper derives and demonstrates a new, purely density-based ab initio\u0000approach for calculation of the energies and properties of many-electron\u0000systems. It is based upon the discovery of relationships that govern the\u0000\"mechanics\" of the electron density -- i.e., relations that connect its\u0000behaviors at different points in space. Unlike wave mechanics or prior\u0000electron-density-based implementations, such as DFT, this density-mechanical\u0000implementation of quantum mechanics involves no many-electron or one-electron\u0000wave functions (i.e., orbitals). Thus, there is no need to calculate exchange\u0000energies, because there are no orbitals to permute or \"exchange\" within\u0000two-electron integrals used to calculate electron-electron repulsion energies.\u0000In practice, exchange does not exist within quantum density mechanics. In fact,\u0000no two-electron integrals need be calculated at all, beyond a single coulomb\u0000integral for the 2-electron system. Instead, a \"radius expansion method\" is\u0000introduced that permits determination of the two-electron interaction for an\u0000N-electron system from one with (N-1)-electrons. Also, the method does not rely\u0000upon a Schrodinger-like equation or the variational method for determination of\u0000accurate energies and densities. Rather, the above-described results follow\u0000from the derivation and solution of a \"governing equation\" for each number of\u0000electrons to obtain a screening relation that connects the behavior at the\u0000\"tail\" of a one-electron density, to that at the Bohr radius. Solution of these\u0000equations produces simple expressions that deliver a total energy for a\u00002-electron atom that is nearly identical to the experimental value, plus\u0000accurate energies for neutral 3, 4, and 5-electron atoms, along with accurate\u0000one-electron densities of these atoms. Further, these methods scale in\u0000complexity only as N, not as a power of N, as do most other accurate\u0000many-electron methods.","PeriodicalId":501304,"journal":{"name":"arXiv - PHYS - Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190210","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

Extended dissipaton-equation-of-motion approach to study the electronic migration in adatom-graphene composite 研究金刚石-石墨烯复合材料中电子迁移的扩展耗散运动方程方法

arXiv - PHYS - Chemical Physics Pub Date : 2024-09-01 DOI: arxiv-2409.00669

Yu Su, Yao Wang, Zi-Fan Zhu, Yuan Kong, Rui-Xue Xu, YiJing Yan, Xiao Zheng

{"title":"Extended dissipaton-equation-of-motion approach to study the electronic migration in adatom-graphene composite","authors":"Yu Su, Yao Wang, Zi-Fan Zhu, Yuan Kong, Rui-Xue Xu, YiJing Yan, Xiao Zheng","doi":"arxiv-2409.00669","DOIUrl":"https://doi.org/arxiv-2409.00669","url":null,"abstract":"Graphene has garnered significant attention due to its unique properties.\u0000Among its many intriguing characteristics, the tuning effects induced by\u0000adsorbed atoms (adatoms) provide immense potential for the design of\u0000graphene-based electronic devices. This work explores the electronic migration\u0000in the adatom-graphene composite, using the extended\u0000dissipaton-equation-of-motion (DEOM) approach. As an exact dynamics theory for\u0000open quantum systems embedded in environments composed of non-interacting\u0000electrons, the extended DEOM is capable of handling both linear and quadratic\u0000environmental couplings (a certain non-Gaussian effect) which account for the\u0000interactions between the adatom and the graphene substrate. We demonstrate and\u0000analyze the adatom-graphene correlated properties and the tuning effects by\u0000simulating the adatom spectral functions with varied Coulomb repulsion\u0000strengths. This work offers not only advanced theoretical methods but also new\u0000insights into the theoretical investigation of complex functional materials\u0000such as graphene-based electronic devices.","PeriodicalId":501304,"journal":{"name":"arXiv - PHYS - Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224807","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

General Quantum Alchemical Free Energy Simulations via Hamiltonian Interpolation 通过哈密顿插值进行通用量子炼金术自由能模拟

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-30 DOI: arxiv-2408.17002

Chenghan Li, Xing Zhang, Garnet Kin-Lic Chan

引用次数: 0

QUEST#4X: an extension of QUEST#4 for benchmarking multireference wavefunction methods QUEST#4X：QUEST#4的扩展，用于多参考波函数方法的基准测试

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-30 DOI: arxiv-2409.00302

Yangyang Song, Ning Zhang, Yibo Lei, Yang Guo, Wenjian Liu

{"title":"QUEST#4X: an extension of QUEST#4 for benchmarking multireference wavefunction methods","authors":"Yangyang Song, Ning Zhang, Yibo Lei, Yang Guo, Wenjian Liu","doi":"arxiv-2409.00302","DOIUrl":"https://doi.org/arxiv-2409.00302","url":null,"abstract":"Given a number of datasets for evaluating the performance of single reference\u0000methods for the low-lying excited states of closed-shell molecules, a\u0000comprehensive dataset for assessing the performance of multireference methods\u0000for the low-lying excited states of open-shell systems is still lacking. For\u0000this reason, we propose an extension (QUEST#4X) of the radial subset of\u0000QUEST#4 [J. Chem. Theory Comput. 2020, 16, 3720] to cover 110 doublet and 39\u0000quartet excited states. Near-exact results obtained by iCIPT2 (iterative\u0000configuration interaction with selection and second-order perturbation\u0000correction) are taken as benchmark to calibrate SDSCI (static-dynamic-static\u0000configuration interaction) and SDSPT2 (static-dynamic-static second-order\u0000perturbation theory), which are minimal MRCI and CI-like perturbation theory,\u0000respectively. It is found that SDSCI is very close in accuracy to ic-MRCISD\u0000(internally contracted multireference configuration interaction with singles\u0000and doubles), although its computational cost is just that of one iteration of\u0000the latter. Unlike most variants of MRPT2, SDSPT2 treats single and multiple\u0000states in the same way, and performs similarly as MS-NEVPT2 (multi-state\u0000n-electron valence second-order perturbation theory). These findings put the\u0000SDS family of methods (SDSPT2, SDSCI, and iCIPT2, etc.) on a firm basis.","PeriodicalId":501304,"journal":{"name":"arXiv - PHYS - Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224804","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

Propellant Discovery For Electrospray Thrusters Using Machine Learning 利用机器学习发现电喷推进器的推进剂

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-30 DOI: arxiv-2408.16951

Rafid Bendimerad, Elaine Petro

引用次数: 0

On the key kinetic interactions between NOx and unsaturated hydrocarbons: H-atom abstraction from C3-C7 alkynes and dienes by NO2 氮氧化物与不饱和碳氢化合物之间的关键动力学相互作用：二氧化氮从 C3-C7 烯炔和二烯中抽取 H 原子

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-30 DOI: arxiv-2408.17277

Zhengyan Guo, Hongqing Wu, Ruoyue Tang, Xinrui Ren, Ting Zhang, Mingrui Wang, Guojie Liang, Hengjie Guo, Song Cheng

{"title":"On the key kinetic interactions between NOx and unsaturated hydrocarbons: H-atom abstraction from C3-C7 alkynes and dienes by NO2","authors":"Zhengyan Guo, Hongqing Wu, Ruoyue Tang, Xinrui Ren, Ting Zhang, Mingrui Wang, Guojie Liang, Hengjie Guo, Song Cheng","doi":"arxiv-2408.17277","DOIUrl":"https://doi.org/arxiv-2408.17277","url":null,"abstract":"An adequate understanding of NOx interacting chemistry is a prerequisite for\u0000a smoother transition to carbon lean and carbon free fuels such as ammonia and\u0000hydrogen. In this regard, this study presents a comprehensive study on the H\u0000atom abstraction by NO2 from C3 to C7 alkynes and dienes forming 3 HNO2 isomers\u0000(i.e., TRANS HONO, HNO2, and CIS HONO), encompassing 8 hydrocarbons and 24\u0000reactions. Through a combination of high level quantum chemistry computation,\u0000the rate coefficients for all studied reactions, over a temperature range from\u0000298 to 2000 K, are computed based on Transition State Theory using the Master\u0000Equation System Solver program with considering unsymmetric tunneling\u0000corrections. Comprehensive analysis of branching ratios elucidates the\u0000diversity and similarities between different species, different HNO2 isomers,\u0000and different abstraction sites. Incorporating the calculated rate parameters\u0000into a recent chemistry model reveals the significant influences of this type\u0000of reaction on model performance, where the updated model is consistently more\u0000reactive for all the alkynes and dienes studied in predicting autoignition\u0000characteristics. Sensitivity and flux analyses are further conducted, through\u0000which the importance of H atom abstractions by NO2 is highlighted. With the\u0000updated rate parameters, the branching ratios in fuel consumption clearly\u0000shifts towards H atom abstractions by NO2 while away from H atom abstractions\u0000by OH. The obtained results emphasize the need for adequately representing\u0000these kinetics in new alkyne and diene chemistry models to be developed by\u0000using the rate parameters determined in this study, and call for future efforts\u0000to experimentally investigate NO2 blending effects on alkynes and dienes.","PeriodicalId":501304,"journal":{"name":"arXiv - PHYS - Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224806","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

Including photoexcitation explicitly in trajectory-based nonadiabatic dynamics at no cost 在基于轨迹的非绝热动力学中不计成本地明确纳入光激发

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-30 DOI: arxiv-2408.17359

Jiří Janoš, Petr Slavíček, Basile F. E. Curchod

引用次数: 0

Frequency-Dependent Conductivity of Concentrated Electrolytes: A Stochastic Density Functional Theory 浓缩电解质随频率变化的电导率：随机密度泛函理论

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-30 DOI: arxiv-2408.17427

Haggai Bonneau, Yael Avni, David Andelman, Henri Orland

引用次数: 0

A High-Temperature Thermocouple Development by Additive Manufacturing: Tungsten-Nickel (W-Ni) and Molybdenum (Mo) Integration with Ceramic Structures 利用增材制造技术开发高温热电偶：钨镍（W-Ni）和钼（Mo）与陶瓷结构的整合

arXiv - PHYS - Chemical Physics Pub Date : 2024-08-09 DOI: arxiv-2408.04800

Azizul Islam, Vamsi Borra, Pedro Cortes

{"title":"A High-Temperature Thermocouple Development by Additive Manufacturing: Tungsten-Nickel (W-Ni) and Molybdenum (Mo) Integration with Ceramic Structures","authors":"Azizul Islam, Vamsi Borra, Pedro Cortes","doi":"arxiv-2408.04800","DOIUrl":"https://doi.org/arxiv-2408.04800","url":null,"abstract":"Additive manufacturing holds more potential to enable the development of\u0000ceramic-based components. Ceramics offer high resistance to heat, high fracture\u0000toughness, and are extremely corrosion resistant. Thus, ceramics are widely\u0000used in sectors such as the aerospace industry, automotive, microelectronics,\u0000and biomedicine. Using various additive manufacturing platforms, ceramics with\u0000complex and uniquely designed geometry can be developed to suit specific\u0000applications. This project aims at innovating high-temperature thermocouples by\u0000embedding conductive metal pastes into a ceramic structure. The paste used\u0000includes tungsten, molybdenum, and antimony. The metal pastes are precisely\u0000extruded into a T-shaped trench inside the ceramic matrix. Following specific\u0000temperature ranges, the ceramic matrix is sintered to improve the properties of\u0000the material. The sensors produced can function at extremely high temperatures\u0000and are thereby suitable for high-temperature environments. Comparative testing\u0000of the 3D sintered sensors with conventional temperature sensors shows high\u0000correlation between the two classes of sensors. The resulting R-squared value\u0000of 0.9885 is satisfactory which implies the reliability and accuracy of 3D\u0000sintering sensors are satisfactory in temperature sensing applications.","PeriodicalId":501304,"journal":{"name":"arXiv - PHYS - Chemical Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141935822","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