International Journal Of Quantum Chemistry Research Articles

Erratum to: Optical response of plasma processed quantum dot under the external fields

Published online 2020 in Wiley InterScience (International Journal of Quantum Chemistry - Wiley Onlinehttps://onlinelibrary.wiley.com). https://doi.org/10.1002/qua.26564 An errata was determined in the paper, which do not affect the results in any way. Throughout the paper, all electric field values should be multiplied by 106 coefficient. The results in the paper were obtained for the electric field values multiplied by the 106 coefficient. However, this coefficient was overlooked at the time of writing.

Per-Olov Löwdin – father of quantum chemistry

ABSTRACTDuring 2016, we celebrate the 100th anniversary of the birth of Per-Olov Löwdin. He was appointed to the first Lehrstuhl in quantum chemistry at Uppsala University in 1960. Löwdin introduced quantum chemistry as a field in its own right by formulating its goals, establishing fundamental concepts, like the correlation energy, the method of configuration interaction, reduced density matrices, natural spin orbitals, charge and bond order matrices, symmetric orthogonalisation, and generalised self-consistent fields. His exposition of partitioning technique and perturbation theory, wave and reaction operators and associated non-linear summation techniques, introduced mathematical rigour and deductive order in the interpretative organisation of the new field. He brought the first computer to Uppsala University and pioneered the initiation of ‘electronic brains’ and anticipated their significance for quantum chemistry. Perhaps his single most influential contribution to the field was his education of two generations of future faculty in quantum chemistry through Summer Schools in the Scandinavian Mountains, Winter Institutes at Sanibel Island in the Gulf of Mexico. Per-Olov Löwdin founded the book series Advances in Quantum Chemistry and the International Journal of Quantum Chemistry. The evolution of quantum chemistry is appraised, starting from a collection of cross-disciplinary applications of quantum mechanics to the technologically advanced and predominant field of today, virtually used in all branches of chemistry. The scientific work of Per-Olov Löwdin has been crucial for the development of this new important province of science.

Recognizing Reviewers

Since it was first formalized by the ‘Philosophical Transactions of the Royal Society’ over three centuries ago, the peer review process has been a critical part of scholarly communication, and more broadly, of the scientific method. At the International Journal of Quantum Chemistry (IJQC), we are very grateful for the support of a large pool of reviewers who volunteer their precious time and unique expertise to help us reach publication decisions and to ensure that the articles we publish are useful and relevant to today's quantum chemistry research community. It is indisputable that the continued success of the journal (testified by its all-time-high 2015 impact factor of 2.184) would have not be possible without the support of our reviewers. However, despite its essential role in the scientific process, and while it diverts time and energy from your own research and your own papers and grants, peer review can seem like a daunting, thankless job and this voluntary contribution typically isn't valued by funding agencies or in important career-related decisions, such as hiring, evaluations and promotions. In fact, a recently published Wiley survey of over 3,000 reviewers found that “reviewers strongly believe that reviewing is inadequately acknowledged at present and should carry more weight in their institutions' evaluation process.”1 Whether or not funders and institutions give professional credit for reviewing activities, journals should provide ways to systematically and publicly recognize peer reviewer efforts. To achieve this, Wiley has partnered with Publons, the world's leading peer review recognition platform, after completing a 6-month pilot program that ran in 2015.2 Publons allows researchers to create their own online referee profiles with bios and peer-review activities for all journals they are affiliated with. The partnership with Wiley allows those who peer-review for any of the hundreds of participating journals to effortlessly record every review they have contributed. Because Wiley and Publons also track and verify reviews for rejected manuscripts, no effort goes unrecognized. Publons profiles can be kept private or publicly showcased. Depending on their age, career stage, geographical location and attitude towards peer-reviewer's anonymity, referees may want to choose different levels of details of their reviewer activity to be displayed publicly in their profile. IJQC gives reviewers full control of the display options, including allowing the publication of the reviewed article titles, and even the full text of the reviews—if you choose to do so. While peer-review activities are still rarely counted as research output and are undervalued for hiring and promotions, they nevertheless show that you're an active member of the research community and regarded as an expert by your peers. IJQC and Wiley are proud to help you showcase your reviewer status and important contributions via Publons; we hope you'll take advantage of it. Thank you for your support of the International Journal of Quantum Chemistry! Matteo Cavalleri Editor-in-Chief Top Reviewers, International Journal of Quantum Chemistry – 2016

Special issue on machine learning and quantum mechanics

Special issue on machine learning and quantum mechanics

QCTFF: On the construction of a novel protein force field

In this perspective, we explain the strategy behind QCTFF, the current name for a novel atomistic protein force field. The atoms are constructed using Quantum Chemical Topology (QCT). These topological atoms determine how a system's energy is partitioned. We give a brief account of the results hitherto obtained, and a glimpse of unpublished results. Combining this QCT partitioning with the universal quantum expression of energy, leads to four types of fundamental energy contributions. The first of these is intra‐atomic and the remaining three interatomic: (i) atomic self‐energy, (ii) Coulomb energy, (iii) exchange energy, and (iv) correlation energy. All structural and dynamic effects emerge from the interplay of these contributions. The machine learning method kriging captures well how they change in response to a change in nuclear configuration. Second, the Coulomb energy is represented by a converging multipolar series expansion when the nuclei are sufficiently far apart. © 2015 The Authors International Journal of Quantum Chemistry Published by Wiley Periodicals, Inc.

Erratum: On spin wavefunctions and young orthogonal matrices

Published in International Journal of Quantum Chemistry 2013, 113, 1436 – 1439 (the change is underlined).

ChemInform Abstract: Spectroscopic and Magnetic Investigations of Actinide‐based Nanomagnets

AbstractReview: 31 refs.

A DFT investigation of the interactions of Pd, Ag, Sn, and Cs with silicon carbide

With a view to understand the diffusion of radionuclides through the silicon carbide layers in tristructural isotropic coated fuel particles, density functional theory calculations are applied to assess the interaction of palladium, silver, tin, and caesium with silicon carbide. The silicon carbide molecule (Si2C2), crystalline cubic silicon carbide (β‐SiC), and the (120) ∑5 grain boundary of β‐SiC are investigated to elucidate the differences in the interactions of silicon carbide with these elements. The main stabilizing forces in the PdSi2C2 complex were found to be donor‐acceptor charge transfer (covalent) interactions, the Ag and Sn complexes involve significant contributions from both electrostatic and covalent interactions, while the Cs atom is bonded dominantly by electrostatic forces. For the unconstrained MSi2C2 model, the following energetic ordering was obtained: Pd > Sn > Cs > Ag. The steric constraints in the bulk SiC and on the grain boundary change the order of binding energies to Pd > Ag > Sn > Cs in the interstitials and Pd > Sn > Ag > Cs in vacancies and at the grain boundary. By comparing the incorporation energies in the solid phases, it is possible to group these elements by similarities in the patterns of incorporation energies. Silver and palladium form a group with carbon, tin is grouped with silicon, and caesium is on its own. © 2014 European Commission. International Journal of Quantum Chemistry published by Wiley Periodicals, Inc.

Spectroscopic and magnetic investigations of actinide‐based nanomagnets

Magnetic exchange is an essential feature of transition‐metal nanomagnets because it combines the relatively low spin‐only moments of several ions into a “giant spin” ground state, which can make slow magnetic relaxation very favorable in an axially anisotropic environment. In contrast, most of the early research on lanthanide‐based complexes focused on single‐ion magnets, where the required large moment is generated by the unquenched orbital contribution (which is parallel to the spin in heavy rare earths). With their unfilled 5f electronic shell being on the verge between localization and itinerancy, actinides are expected to combine the best of both 3d and 4f metals in terms of exchange and anisotropy, and are therefore under consideration as potential building blocks for the next generation of single‐molecule magnets. In this Perspective, a review of the recent development in this field is given, and some discrepancies between the spectroscopic and magnetic data are discussed. © 2014 European Commission. International Journal of Quantum Chemistry published by Wiley Periodicals, Inc.

Challenges in the theoretical description of nanoparticle reactivity: Nano zero‐valent iron

The reactivity of iron atoms, clusters, and nanoparticles (nZVI) is of increasing interest owing to their important practical applications, ranging from the steel industry to water remediation technologies. Here, we provide an overview of computational methods and models that can be applied to study nanoscale zero‐valent iron (nZVI) reactions and discuss their benefits and limitations. We also report current progress in calculations through recent examples treating the reactivity of nZVI particles. Finally, we consider the potential use of highly accurate methods with favorable scaling (such as quantum Monte Carlo or random phase approximation), which are currently considered too computationally expensive but are expected to become more amenable in the future as computer power increases. © 2014 The Authors International Journal of Quantum Chemistry Published by Wiley Periodicals, Inc.

Uncertainty quantification in thermochemistry, benchmarking electronic structure computations, and Active Thermochemical Tables

The accepted convention for expressing uncertainties of thermochemical quantities, followed by virtually all thermochemical tabulations, is to provide earnest estimates of 95% confidence intervals. Theoretical studies frequently ignore this convention, and, instead, provide the mean absolute deviation, which underestimates the recommended thermochemical uncertainty by a factor of 2.5–3.5 or even more, and thus may vitiate claims that “chemical accuracy” (ability to predict thermochemical quantities within ±1 kcal/mol) has been achieved. Furthermore, copropagating underestimated uncertainties for theoretical values with uncertainties found in thermochemical compilations produces invalid uncertainties for reaction enthalpies. Two groups of procedures for determining the accuracy of computed thermochemical quantities are outlined: one relying on estimates that are based on experience, the other on benchmarking. Benchmarking procedures require a source of thermochemical data that is as accurate and reliable as possible. The role of Active Thermochemical Tables in benchmarking state‐of‐the‐art electronic structure methods is discussed. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. International Journal of Quantum Chemistry published by Wiley Periodicals, Inc.

P.-O. Löwdin and the International Journal of Quantum Chemistry: A kaleidoscopic agenda for quantum chemistry

This is a article about P.-O. Lowdin's life, his work in shaping quantum chemistry into a mature discipline at the intersection of mathematics, physics, chemistry, and biology, and his founding of the International Journal of Quantum Chemistry in 1967. Unavoidably, it is, also, a article reflecting our views about the history of quantum chemistry. We attempt to convey the complexities in the becoming of a subdiscipline, like quantum chemistry, where a variety of factors will have to be taken into consideration for a comprehensive understanding of its historical developments: the relations of chemists to the Heisenberg-Schrodinger formulation of quantum mechanics after 1926, the institutional dynamics centered around the establishment of new courses and chairs, the research agendas and the vying for dominance within the community of quantum chemists, the methodological, and philosophical issues that have never left the quantum chemists indifferent, and, of course, the dramatic role of the computer in transforming the culture for actually practicing quantum chemistry. Furthermore, attracted by American history, culture, and ways of life, Lowdin suggested in the late 1970s that the post-WWII character of quantum chemistry was dependent on its ability to hub a “scientific melting pot,” much like the United States of America which he viewed as a fusion of people from diverse provenances and cultures. In this article, we attempt to investigate another metaphor, that of the “kaleidoscope.” Lowdin believed that quantum chemistry's strength arose from its ability to nurture a multiplicity of heterogeneous cultural elements/subcultures and practices, interacting with each other, exchanging perspectives and modes of action, which circulated in an increasingly extended network of actors and institutional frameworks. © 2013 Wiley Periodicals, Inc.

Theory and calculation for the electronic coupling in excitation energy transfer

Excitation energy transfer (EET) is a process where the electronically excitation is transferred from a donor to an acceptor. EET is widely seen in both natural and in artificial systems, such as light-harvesting in photosynthesis, the fluorescence resonance energy transfer technique, and the design of light-emitting molecular devices. In this work, we outline the theories describing both singlet and triplet EET (SEET and TEET) rates, with a focus on the physical nature and computational methods for the electronic coupling factor, an important parameter in predicting EET rates. The SEET coupling is dominated by the Coulomb coupling, and the remaining short-range coupling is very similar to the TEET coupling. The magnitude of the Coulomb coupling in SEET can vary much, but the contribution of short-range coupling has been found to be similar across different excited states in naphthalene. The exchange coupling has been believed to be the major physical contribution to the short-range coupling, but it has been pointed out that other contribution, such as the orbital overlap effect is similar or even larger in strength. The computational aspects and the subsequent physical implication for both SEET and TEET coupling values are summarized in this work. © 2013 The Authors. International Journal of Quantum Chemistry Published by Wiley Periodicals, Inc.

Why do molecules echo atomic periodicity?

Franck–Condon factors are investigated for sequences of free main-group diatomic molecules. Theory-based Condon loci (parabolas) and Morse-potential loci are plotted on Deslandres tables to verify if they, indeed, follow the largest Franck–Condon factors. Then, the inclination angles of the Condon loci are determined. Thus, entire band systems are quantified by one variable, the angle. For all available isoelectronic sequences, this angle increases from a central minimum toward magic-number molecular boundaries. The theory for the Condon locus gives the angle in terms of the ratio of the upper-state to the lower-state force constants. It is concluded that the periodicity is caused due to the fact that this ratio becomes larger as rare-gas molecules are approached, a trend that probably points to the extreme cases of the rare-gas molecules themselves. Thus, molecular periodicity echoes atomic periodicity in that data plots have extrema at molecules with magic-number atoms, yet it does not echo the details of atomic periodicity in series between those molecules. © 2013 The Authors. International Journal of Quantum Chemistry Published by Wiley Periodicals, Inc.

Quantum chemistry reloaded

When Per-Olov Löwdin founded the International Journal of Quantum Chemistry in 1967 quantum chemistry was entering the modern era, beginning to explore the potential of computers as well as extending its realm beyond the study of atoms and molecules to small systems of biological interest. Löwdin's vision for the discipline is reflected in his editorial for the inaugural issue of the journal.[1] Coming into existence through the interactions of physics, chemistry, applied mathematics, and what we now would call computer science, modern quantum chemistry has been a naturally interdisciplinary field from the outset, and IJQC's role is to report and facilitate this interplay of theory, computational algorithms, and applications to atoms, molecules, crystals, and biology, in close connection with experiments. In the nearly half a century since that historic editorial, quantum chemistry has experienced continuous evolution, harvesting the most exciting developments from the parent fields. The rise of materials science research, for example, has brought the challenge of extending the predicting power of quantum chemical calculations to ever larger and more complex systems, whereas the study of chemical reactivity and biological processes requires the accurate simulation of atomic dynamics by first-principles. In the same way, the introduction and optimization of new, powerful, and sophisticated spectroscopic techniques calls for increasingly accurate theoretical approaches for their interpretation, and computational algorithms and software must be developed to adapt to new, ever more powerful computer architectures: from massive parallel supercomputers with hundreds of thousands of processors to systems based on graphical chips. Finally, the application of quantum information concepts to chemistry[2] could drive a new beginning for quantum chemistry, similar to that experienced with the advent of electronic computers 50 years ago. Mirroring quantum chemistry's path, IJQC must also evolve to continue to serve its original mission of fostering the exchange of ideas between researchers from all aspects of the discipline. A journal at the service of today's quantum chemistry community demands modern publishing processes, and we have been working hard to improve our manuscript handling and production procedures to ensure that your research is available to the community as soon as possible. These efforts have resulted in the reduction of the acceptance to online publication time to a very competitive 15 working days on average. Our team of professional in-house editors is focused on delivering rapid and rigorous peer-review, keeping well in sight the journal's role in providing interdisciplinary communication and scientific insight, and not just simple numerical results. With our new Reviews and Tutorials series,[3] we plan to echo the versatility and variety of modern quantum chemistry, and by making these articles free to access we hope to give everybody an opportunity to discover new aspects of this stimulating discipline. Moreover, our most exciting articles are now highlighted through the very popular ChemistryViews.org and MaterialsViews.com, Wiley's chemistry and materials science news sites, to guarantee them the great exposure they deserve even beyond the theoretical chemistry community. Finally, we hope that you have already appreciated IJQC's new look, which premiered last year with issue 17/2012. In addition to full-page cover images, highlighting some of the most interesting articles of every issue, we have introduced a graphical table of contents to guide you quickly to the papers of your interest in the journal, both online and in print. We look forward to what the future holds in store for quantum chemistry. Whatever this may be, you will read it on the pages of IJQC. Enjoy the “reloaded” International Journal of Quantum Chemistry !

Special Issue: Seventh congress of the international society for theoretical chemical physics

This volume collects 58 selected papers from the scientific contributions presented at the Seventh Congress of the International Society for Theoretical Chemical Physics (ISTCP-VII), organized by t ...

Solvent effects in Spectroscopy and Reactivity of Molecular Liquids: Contributions from Sylvio Canuto

AbstractSylvio Canuto obtained his PhD in 1979 at the University of Uppsala (Sweden). His scientific contributions include about 180 well‐cited articles. He is presently a fulltime Professor at the Institute of Physics of the Universidade de São Paulo, São Paulo, Brazil. He was a member of the Editorial Board of Chemical Physics Letters for two terms and is presently serving on the Editorial Board of the International Journal of Quantum Chemistry, (since 2001), Journal of Computational Methods in Science and Engineering (since 2006), Specialist Editor of Computer Physics Communications (1987–1989, 2002–2007), and of Research Letters in Physical Chemistry (from 2007). He is a member of the Scientific Advisory Board of the Journal of the Argentine Chemical Society and was an Associate Editor of the Brazilian Journal of Physics for 10 years. His scientific interests lie in Many Bodies Theory, in Computer Simulations and Molecular Modeling, specially Solvent Effects in Spectroscopy and the Reactivity of Molecular Liquids. This short communication is a brief account of his contribution to this latter field, and as such it is necessarily limited in scope and somewhat arbitrary in the choice of the articles here discussed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010

Introduction

This issue of the International Journal of Quantum and Computational Chemistry consists of contributions coming from the 12th V.A. Fock Meeting on Quantum and Computational Chemstry held in Kazan (Republic of Tatarstan, Russia) located on the banks of the Wolga river from 19 to 23 October 2009. This was the annual meeting of the series of the V.A. Fock Meetings of which the first was held in December of the year 1998 in celebration of the 100-th anniversary of the birth of Prof. V.A. Fock of the St. Petersburg (Leningrad) University, whose works such as the ubiquitous Hartree–Fock approximation are central to physical chemistry and chemical physics. These Meetings are attended by the established researches as well as by younger scientists from leading reasearch centers of Russia. The 2009 meeting was attended by participants from Moscow, St. Petersburg, Krasnodar, Bashkir State Universities, Kurnakov Institute of General and Inorganic Chemistry of RAS, Boreskov Institute of Catalysis of SB RAS (Novosibirsk), and many others. The Meetings of this Series are sponsored by the Scientific Council on Chemical Structure and Reactivity of RAS. The 2009 Meeting as the previous ones was also supported by the Section of Quantum and Computational Chemistry at the D.I. Mendeleev Chemical Society of Russia. Financial support for this activity comes from the Russian Foundation for Basic Research (Grant No. 09-03-06076). The topic presented at the Fock Meeting range from theoretical foundations of quantum chemistry to its applications related to structure dynamics and reactivity and from diatomics to solid state and biomolecules. The applications involve small molecules as well as biomolecules and condensed-phase systems. This Meeting would be not possible without kind support and assistance of many people. Among them Prof. A.L. Buchachenko—the chairman of the Division for Computational Chemistry at the Mendeleev Society and the chairman of the RAS Council on Chemical Structure and Reactivity. Key roles were played by the Rector of the Kazan State technological University Prof. German S. D'yakonov and the chairman of the local Organizing Committee Prof. R.R. Nazmutdinov, whose solutions to all problems made the sessions of the Meeting successful and comfortable. Finally, Prof. Yngve Öhrn (Florida, USA) is acknowledged for his devotion in organizing the preparation and publication of these Proceedings in the International Journal of Quantum Chemistry.

Preface

The 35th Congress of Theoretical Chemists of Latin Expression (QUITEL/CHITEL) was held from September 18 to 22, 2009, on San Andres Island, Colombia. About 170 participants from 27 countries gathered for 5 days of lectures, poster sessions and informal discussions. The Congress took place at the Sunrise Beach Hotel, set on the north-eastern tip of San Andres, overlooking the Caribbean Sea, in premises endowed with the latest multimedia equipment. This 35th version of the QUITEL/CHITEL Congress, held for the first time in Colombia, followed the format of previous meetings, that is, all lectures were conducted in romance languages. The program consisted of 24 plenary lectures, 37 short oral communications and 3 poster sessions. These proceedings contain papers from many of the Congress sessions, and have been subject to the normal refereeing procedures of the International Journal of Quantum Chemistry. The organizers are pleased to acknowledge the support given to the QUITEL/CHITEL 2009 Congress by Universidad Nacional de Colombia, Universidad de Cordoba, Universidad de Antioquia, Universidad del Valle, Universidad Santiago de Cali, Universidad Industrial de Santander, COLCIENCIAS, MInisterio de Educacion de Colombia and ICETEX. The contributions of our sponsors enabled us to maintain the high-quality standard of this QUITEL/CHITEL meeting. Special thanks go to Dr. Maria Tubio, who offered her invaluable assistance in handling the numerous details involved in organizing an international scientific meeting, including the local arrangements, registration process and social activities. We are grateful to all oral speakers and poster presenters for making this congress a stimulating experience.

Preface: Proceedings of the XV Brazilian Symposium of Theoretical Chemistry

The Brazilian Symposium of Theoretical Chemistry (SBQT) is a traditional scientific meeting in the area of Quantum Chemistry and Molecular Physics. This symposium occurs every two years. This 15th version gathered about 300 participants from several countries, mostly from Latin America. In this XV SBQT a total of 13 plenary and 40 short lectures were delivered. In addition, around 390 posters were presented, by both senior scientists as well as students. This issue collects a part of the scientific contributions presented at the meeting. This version occurred during the period of October 18th – 21st, 2009, in Poços de Caldas, Minas Gerais, Brazil. The Organizing Committee of this XV SBQT version was composed by Léo Degrève (USP), Alexandre Braga da Rocha (UFRJ), Munir Salomão Skaf (Unicamp), Paulo Augusto Netz (UFRGS), Regiane de Cássia Maritan Ugulino de Araújo (UFPB), Stella Maris Resende (UFSJR) and Geraldo Magela e Silva (UnB) and we express our gratitude to their efforts in making this an interesting event. The success of this Symposium would be hardly possible without the financial support from many agencies in special, CNPq, CAPES, and the state funding agencies FAPESP (São Paulo), FACEPE (Pernambuco), FAPEMIG (Minas Gerais), FAPERJ (Rio de Janeiro) and FAPDF (Brasilia). Universities over the country provided additional and important support. Finally, we warmly thank the Editorial Assistant Mr. James F. Folks for considerable dedication in handling the online submission and processing the manuscripts submitted for publication. We also thank Prof. Erkki Brändas and Prof. Yngve Öhrn, the Editors–in–Chief of the International Journal of Quantum Chemistry, for their commitment and support for the publication of these proceedings.