{"title":"Multiscale Modeling of Charge Transfer Processes in Organic Semiconductors","authors":"Shiwei Yin","doi":"10.1063/9780735422377_006","DOIUrl":"https://doi.org/10.1063/9780735422377_006","url":null,"abstract":"The relationship between molecular structure and macroscopic charge mobility plays an important role in the design of organic semiconductors. In this respect, the molecular packing is the starting point that governs the electron coupling, energetic landscapes, and electron polarization (EP) energies of the charge carriers. The molecular packing is strongly dependent on the intermolecular interaction potentials. During charge transfer (CT) processes, the intermolecular potentials are related to electron state changes in which the charged molecule moves from one site to another site. Thus, traditional force fields cannot express these electron processes. To this end, state-specific polarizable force fields (SS-PFFs) derived from quantum mechanics were developed to describe the intermolecular interactions between the neutral molecules and charged molecules. The influence of the condensed phase on the EP energies and reorganization energies of CT reactions in organic solids can be explicitly discussed using SS-PFFs. The molecular descriptors of the electrostatic potentials are used to relate the condensed-phase effects and molecular structure. In this way, we can obtain a basic physical picture to guide the design of organic semiconducting molecular materials.","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132265353","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}
{"title":"Theory and Practice in Constant Potential Molecular Dynamics Simulations","authors":"S. Tee","doi":"10.1063/9780735422377_004","DOIUrl":"https://doi.org/10.1063/9780735422377_004","url":null,"abstract":"Understanding electrode–electrolyte interfaces at the molecular level is crucial for further progress in electrochemistry, with numerous practical applications in store for society. Molecular dynamics (MD) is a natural technique of choice for accessing molecular-level detail, and the constant potential method (CPM) enables physically realistic and computationally feasible simulations of large systems between conductive electrodes with a specified potential difference. As such, this review aims to introduce readers to the most important concepts of the CPM, such as dynamic charge updating methods, importance sampling in the constant potential ensemble, and optimal periodic boundary conditions for calculating long-range electrostatic interactions. The CPM has been used to study the capacitance of room-temperature ionic liquid supercapacitors and the relationship with electrolyte layering near charged electrodes, the mechanisms and kinetics of charging and discharging, and the utility of nanoporous electrodes in achieving ionic nanoconfinement and superionic states. These areas highlight the flexibility of CPM MD and the additional physical realism that is achieved over simpler fixed charge methods when studying complex electrolyte–electrode interfaces. Nonetheless, there are many potentially fruitful ways to further optimize CPM MD simulations, alongside numerous areas where the application of this technique could yield novel and interesting results.","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121627743","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}
{"title":"Numerical Simulation of Electrified Solid–Liquid Interfaces","authors":"Yun Wang","doi":"10.1063/9780735422377_003","DOIUrl":"https://doi.org/10.1063/9780735422377_003","url":null,"abstract":"The electrified electrode–electrolyte interface plays a central role in electrochemical processes because it is in this region that the redox reactions occur. However, current understanding of the structural and electronic properties of electrified interfaces remains limited. To narrow this knowledge gap, numerical modeling techniques at various scales have recently been developed. In this chapter, the influence of the applied bias potential on interfacial processes is explored. Recent developments in classical force-field-based molecular dynamics and first-principles electrochemistry simulation methodologies for simulating the dynamic nature of these interfaces are summarized with consideration of the requirement for charge neutrality and alignment of the reference potential. Relevant case studies are also presented to highlight the advantages and disadvantages of the various methods.","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114510919","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}
{"title":"Theory–Experiment Gap","authors":"Junxian Liu, Yun Wang","doi":"10.1063/9780735422377_001","DOIUrl":"https://doi.org/10.1063/9780735422377_001","url":null,"abstract":"Electrochemistry plays a paramount role in both science and manufacturing, in addition to offering promising solutions for the conversion and storage of sustainable energy to protect the environment. To promote the further development of electrochemical processes, a more detailed description and better fundamental understanding are required. This calls for deep insights into the structure and dynamics of electrode–electrolyte interfaces at the atomic level, taking various external working conditions into account. By virtue of the evolution of modern chemistry, numerical simulations have been able to capture the complexity of these processes with increasing success, including consideration of the presence of the electrical double layer, explicit electrode–solvent interfaces, and the applied potential. This chapter highlights the status of current theoretical studies, demonstrating the availability of well-defined models and more accurate methods. Using selected examples, the gap between experiments and current theoretical work considering the complex operating environment of electrochemical processes is discussed. We believe that the development of more reliable modeling approaches and the application of multiscale simulations are crucial for further advancing the understanding of electrochemical processes.","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"329 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120969720","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}
{"title":"First-Principles Calculations for Electrochemical Reaction Modeling: An Introduction to Methods and Applications","authors":"Mingtao Li, Dongyu Liu, Lubing Li","doi":"10.1063/9780735422377_002","DOIUrl":"https://doi.org/10.1063/9780735422377_002","url":null,"abstract":"First-principles calculations based on density functional theory (DFT) play an essential role in state-of-the-art studies aimed at understanding electrochemical reactions and designing corresponding electrode materials. These calculations can be applied to determine the geometric and electronic structures of materials, evaluate the barriers for reactant adsorption and subsequent reactions, and explore reaction mechanisms from a microscale perspective, and they have recently emerged as a popular approach in many electrochemistry-related fields, such as electrocatalysis and batteries. In this chapter, we present an overview of the first-principles calculation approach with an emphasis on providing a pedagogical introduction of its applications in understanding electrochemical processes. First, some physical and mathematical concepts relating to DFT are presented. Next, we turn to a discussion of how to investigate microscale electrochemical processes using DFT calculations. Some practical methods and processes for simulating real systems with computational models are also described. Finally, we provide some examples to demonstrate the power of first-principles calculations in electrochemical studies. Our aim is to give beginners an overview of this approach and a practical guide for its application to electrochemical reactions.","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121582655","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}
{"title":"Index","authors":"Yun Wang","doi":"10.1063/9780735422377_index","DOIUrl":"https://doi.org/10.1063/9780735422377_index","url":null,"abstract":"","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127311638","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}
{"title":"Mean-Field and Modified Poisson–Boltzmann Approaches for Modeling Electrochemical Energy Storage Systems","authors":"M. S. Santos","doi":"10.1063/9780735422377_005","DOIUrl":"https://doi.org/10.1063/9780735422377_005","url":null,"abstract":"","PeriodicalId":231463,"journal":{"name":"Multiscale Modeling of Electrochemical Reactions and Processes","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122821417","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}