Qualitative Valence-Bond Descriptions of Electron-Rich Molecules: Pauling “3-Electron Bonds” and “Increased-Valence” Theory

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Publisher : Springer Science & Business Media
ISBN 13 : 3642932169
Total Pages : 275 pages
Book Rating : 4.6/5 (429 download)

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Book Synopsis Qualitative Valence-Bond Descriptions of Electron-Rich Molecules: Pauling “3-Electron Bonds” and “Increased-Valence” Theory by : R. D. Harcourt

Download or read book Qualitative Valence-Bond Descriptions of Electron-Rich Molecules: Pauling “3-Electron Bonds” and “Increased-Valence” Theory written by R. D. Harcourt and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides qualitative molecular orbital and valence-bond descriptions of the electronic structures for electron-rich molecules, with strong emphasis given to the valence-bond approach. Electron-rich molecules form an extremely large class of molecules, and the results of quantum mechanical studies from different laboratories indicate that qualitative valence-bond descriptions for many of these molecules are incomplete in so far as they usually omit "long-bond" Lewis structures from elementary descriptions of bonding. For example, the usual representation for the electronic structure of the ground-state for 03 involves resonance between the (+1 o and Until standard Lewis structures ~ ~ (-I . b:'" ~d· . . . . , recently, any contribution to resonance of the "long-bond" (or spin-paired o •• / •• ,. . has been largely ignored. diradica~ Lewis structure However, it :0 . 0. . e-. . . . . ______ " has now been calculated to be a very important structure. For the ground-states of numerous other systems, calculations also indicate that "long-bond" structures are more important than is usually supposed, and therefore they should frequently be included in qualitative valence-bond descriptions of electronic structure. The book describes how this may be done, and some of the resulting consequences for the interpretation of the electronic structure, bond properties and reactivities of various electron-rich molecules. When appropriate, molecular orbital and valence bond descriptions of bonding are compared, and relationships that exist between them are derived.

Qualitative Valence-bond Descriptions of Electron-rich Molecules

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Publisher : Springer Verlag
ISBN 13 : 9780387115559
Total Pages : 0 pages
Book Rating : 4.1/5 (155 download)

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Book Synopsis Qualitative Valence-bond Descriptions of Electron-rich Molecules by : R. D. Harcourt

Download or read book Qualitative Valence-bond Descriptions of Electron-rich Molecules written by R. D. Harcourt and published by Springer Verlag. This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Qualitative Valence-bond Descriptions of Electron-rich Molecules

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Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (224 download)

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Book Synopsis Qualitative Valence-bond Descriptions of Electron-rich Molecules by :

Download or read book Qualitative Valence-bond Descriptions of Electron-rich Molecules written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Bonding in Electron-Rich Molecules

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Publisher : Springer
ISBN 13 : 331916676X
Total Pages : 328 pages
Book Rating : 4.3/5 (191 download)

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Book Synopsis Bonding in Electron-Rich Molecules by : Richard D. Harcourt

Download or read book Bonding in Electron-Rich Molecules written by Richard D. Harcourt and published by Springer. This book was released on 2015-10-30 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This second edition was updated to include some of the recent developments, such as “increased-valence” structures for 3-electron-3-centre bonding, benzene, electron conduction and reaction mechanisms, spiral chain O4 polymers and recoupled-pair bonding. The author provides qualitative molecular orbital and valence-bond descriptions of the electronic structures for primarily electron-rich molecules, with strong emphasis given to the valence-bond approach that uses “increased-valence” structures. He describes how “long-bond” Lewis structures as well as standard Lewis structures are incorporated into “increased-valence” structures for electron-rich molecules. “Increased-valence” structures involve more electrons in bonding than do their component Lewis structures, and are used to provide interpretations for molecular electronic structure, bond properties and reactivities. Attention is also given to Pauling “3-electron bonds”, which are usually diatomic components of “increased-valence” structures for electron-rich molecules.

Valence Bond Theory

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Publisher : Elsevier
ISBN 13 : 0080543499
Total Pages : 837 pages
Book Rating : 4.0/5 (85 download)

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Book Synopsis Valence Bond Theory by : David Cooper

Download or read book Valence Bond Theory written by David Cooper and published by Elsevier. This book was released on 2002-06-05 with total page 837 pages. Available in PDF, EPUB and Kindle. Book excerpt: Valence bond (VB) theory, which builds the descriptions of molecules from those of its constituent parts, provided the first successful quantum mechanical treatments of chemical bonding. Its language and concepts permeate much of chemistry, at all levels. Various modern formulations of VB theory represent serious tools for quantum chemical studies of molecular electronic structure and reactivity. In physics, there is much VB-based work (particularly in semi-empirical form) on larger systems. Importance of TopicThe last decade has seen significant advances in methodology and a vast increase in the range of applications, with many new researchers entering the field.Why This TitleValence Bond Theory succeeds in presenting a comprehensive selection of contributions from leading valence bond (VB) theory researchers throughout the world. It focuses on the vast increase in the range of applications of methodology based on VB theory during the last decade and especially emphasizes recent advances.

Reviews in Computational Chemistry, Volume 20

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Publisher : John Wiley & Sons
ISBN 13 : 0471678848
Total Pages : 485 pages
Book Rating : 4.4/5 (716 download)

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Book Synopsis Reviews in Computational Chemistry, Volume 20 by : Kenny B. Lipkowitz

Download or read book Reviews in Computational Chemistry, Volume 20 written by Kenny B. Lipkowitz and published by John Wiley & Sons. This book was released on 2004-08-16 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: THIS VOLUME, LIKE THOSE PRIOR TO IT, FEATURES CHAPTERS BY EXPERTS IN VARIOUS FIELDS OF COMPUTATIONAL CHEMISTRY. TOPICS COVERED IN VOLUME 20 INCLUDE VALENCE THEORY, ITS HISTORY, FUNDAMENTALS, AND APPLICATIONS; MODELING OF SPIN-FORBIDDEN REACTIONS; CALCULATION OF THE ELECTRONIC SPECTRA OF LARGE MOLECULES; SIMULATING CHEMICAL WAVES AND PATTERNS; FUZZY SOFT-COMPUTING METHODS AND THEIR APPLICATIONS IN CHEMISTRY; AND DEVELOPMENT OF COMPUTATIONAL MODELS FOR ENZYMES, TRANSPORTERS, CHANNELS, AND RECEPTORS RELEVANT TO ADME/TOX. FROM REVIEWS OF THE SERIES "Reviews in Computational Chemistry remains the most valuable reference to methods and techniques in computational chemistry." -JOURNAL OF MOLECULAR GRAPHICS AND MODELING "One cannot generally do better than to try to find an appropriate article in the highly successful Reviews in Computational Chemistry. The basic philosophy of the editors seems to be to help the authors produce chapters that are complete, accurate, clear, and accessible to experimentalists (in particular) and other nonspecialists (in general)." -JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

Atoms, Chemical Bonds and Bond Dissociation Energies

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Publisher : Springer Science & Business Media
ISBN 13 : 3642514928
Total Pages : 182 pages
Book Rating : 4.6/5 (425 download)

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Book Synopsis Atoms, Chemical Bonds and Bond Dissociation Energies by : Sandor Fliszar

Download or read book Atoms, Chemical Bonds and Bond Dissociation Energies written by Sandor Fliszar and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical bonds, their intrinsic energies in ground-state molecules and the energies required for their actual cleavage are the subject of this book. The theory, modelled after a description of valence electrons in isolated atoms, explains how intrinsic bond energies depend on the amount of electronic charge carried by the bond-forming atoms. It also explains how bond dissociation depends on these charges. While this theory vividly explains thermochemical stability, future research could benefit from a better understanding of bond dissociation: if we learn how the environment of a molecule affects its charges, we also learn how it modifies bond dissociation in that molecule. This essay is aimed at theoretical and physical-organic chemists who are looking for new perspectives to old problems.

Hypervirial Theorems

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Publisher : Springer Science & Business Media
ISBN 13 : 3642933491
Total Pages : 383 pages
Book Rating : 4.6/5 (429 download)

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Book Synopsis Hypervirial Theorems by : Francisco M. Fernandez

Download or read book Hypervirial Theorems written by Francisco M. Fernandez and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt:

GRMS or Graphical Representation of Model Spaces

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Publisher : Springer Science & Business Media
ISBN 13 : 3642933475
Total Pages : 197 pages
Book Rating : 4.6/5 (429 download)

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Book Synopsis GRMS or Graphical Representation of Model Spaces by : Wlodzislaw Duch

Download or read book GRMS or Graphical Representation of Model Spaces written by Wlodzislaw Duch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of these notes is to give some simple tools and pictures to physicists and ' chemists working on the many-body problem. Abstract thinking and seeing have much in common - we say "I see" meaning "I understand" , for example. Most of us prefer to have a picture of an abstract object. The remarkable popularity of the Feynman diagrams, and other diagrammatic approaches to many-body problem derived thereof, may be partially due to this preference. Yet, paradoxically, the concept of a linear space, as fundamental to quantum physics as it is, has never been cast in a graphical form. We know that is a high-order contribution to a two-particle scattering process (this one invented by Cvitanovic(1984)) corresponding to a complicated matrix element. The lines in such diagrams are labeled by indices of single-particle states. When things get complicated at this level it should be good to take a global view from the perspective of the whole many-particle space. But how to visualize the space of all many-particle states ? Methods of such visualization or graphical representation of the ,spaces of interest to physicists and chemists are the main topic of this work.

Time-Dependent Reactivity of Species in Condensed Media

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Publisher : Springer Science & Business Media
ISBN 13 : 3642933262
Total Pages : 158 pages
Book Rating : 4.6/5 (429 download)

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Book Synopsis Time-Dependent Reactivity of Species in Condensed Media by : Andrzej Plonka

Download or read book Time-Dependent Reactivity of Species in Condensed Media written by Andrzej Plonka and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: These notes on the use of one particular form of the time-dependent rate constant to describe the reaction patterns in condensed media have been put together primarily to encourage chemists to try and accept this new way of experimental data treatment. A number of applications is shown and interpretative aspects are discussed. Emphasized are the problems that need to be currently solved. Some of them are also of current interest in condensed phase physics from which the chemical kinetics benefits a great deal. It was inevitable that the choice of subject matter from both rapidly expanding fields and its form of pre sentation reflect to some extent the author's own interests and some important topics are treated briefly or even omitted. Fully recognizing this, I would like to acknowledge with gratitude the contributions to the subject of all my coworkers in the Laboratories of Lodz, Detroit Mi, MUlheim/Ruhr, and Houston Tx, and of those who helped me in preparing this text. Dr. Wlodzi~ierz Lefik and my son WojciecQ recalculated most of the experimental results, Mrs. Aleksandra Karczewska redrew all the figures. Special thanks go to my wife Ewa for her invaluable assistance in all works and for the final form of the text. AP Lodz, February 1986 CONTENTS 1. Introduction 1 2. Reaction kinetics of species trapped in glassy matrices 6 Excess electrons (6): Post-irradiated decay (6). Spectral relaxation (11). Photostimulated decay (15). Photostimu lated conversion into trapped hydrogen atoms (17). Radio luminescence kinetics (21).

Electrochemistry on Liquid/Liquid Interfaces

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Publisher : Springer Science & Business Media
ISBN 13 : 3642489109
Total Pages : 111 pages
Book Rating : 4.6/5 (424 download)

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Book Synopsis Electrochemistry on Liquid/Liquid Interfaces by : Petr Vanysek

Download or read book Electrochemistry on Liquid/Liquid Interfaces written by Petr Vanysek and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: A charge transfer across the interface between two immiscible liquid media has an important role both in nature and in man-designed applications. Ion transfer across the biological membranes, behavior of ion-selective electrodes with liquid membranes and similar sensors, extraction processes, phase transfer catalysis and applications in electroanalytical chemistry can serve as examples. Present interest in the interface between two immiscible electrolytes (liquid liquid or L/L interface) was originated by Koryta's idea (Koryta, Vanysek and Brezina 1976) that the interface between immiscible liquids could serve as a simple model for one half of a biological membrane in the contact with the surrounding electrolyte. It was also Koryta who started using the acronym ITIES (Interface between Two Immiscible Electrolyte Solutions) which generally encompasses all the phenomena discussed in this book. Physiological and electrochemical investigations have certainly well established tradition. In his classic experiments with frog thighs Luigi Galvani discovered in 1791 relationship between electricity and nerves and muscles. As outlined by Koryta and Stullk (1983) in the introduction to their book, the study of electrophysiological phenomena did not progress much for several decades and only a few experiments were performed. For instance M. Faraday (Williams, 1965) studied the electricity produced by an electric fish and Du Bois-Reymond (1848) suggested that the surface of biological formations have properties similar to the electrode of a galvanic cell. However, the properties of biological membrane could not be explained before the first concept of electrochemistry was postulated.

Perspectives in Theoretical Stereochemistry

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Publisher : Springer Science & Business Media
ISBN 13 : 3642932665
Total Pages : 270 pages
Book Rating : 4.6/5 (429 download)

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Book Synopsis Perspectives in Theoretical Stereochemistry by : I. Ugi

Download or read book Perspectives in Theoretical Stereochemistry written by I. Ugi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stereochemistry is the part of chemistry that relates observable prop erties of chemical compounds to the structure of their molecules, i. e. the relative spatial arrangement of their constituent atoms. In classical stereochemistry, the spatial arrangements relevant for interpreting and predicting a given chemical property are customarily described by geometric features/ symmetries in some suitably chosen rigid model of the molecule The solution of stereochemical problems involving single molecular species is the danain of the geometry based approaches, such as the methods of classical stereochemistry, molecular mechanics and quantum chemistry. The molecules of a pure chemical compound form generally an ensemble of molecular individuals that differ in geometry and energy. Thus it is generally impossible to represent a chemical compund adequately by the geo metry of a rigid molecular model. In modern stereochemistry it is often necessary to analyze molecular relation within ensembles and families of stereoisomers and permutation isomers, including molecules whose geometric features are changing with time. Accordingly, there is definitely a need for new types of ideas, concepts, theories and techniques that are usable beyond the scope of customary methodology. This is why the present text was written.

Potential Energy Functions in Conformational Analysis

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Publisher : Springer Science & Business Media
ISBN 13 : 3642455913
Total Pages : 241 pages
Book Rating : 4.6/5 (424 download)

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Book Synopsis Potential Energy Functions in Conformational Analysis by : Kjeld Rasmussen

Download or read book Potential Energy Functions in Conformational Analysis written by Kjeld Rasmussen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: I get by with a little help from my friends The Beatles: Sgt. Pepper This book should have been in Danish. Any decent person must be able to express himself in his mother's tongue, also when expounding scientific ideas and results. Had I stuck to this ideal, the book would have been read by very few people, and, indeed, appreciated by even fewer. Having it publ ished in English gives me a chance to fulfill one ambition: to be read and judged by the international scientific community. Another reason is that the majority of my professional friends are regrettably unread in Danish, just as I am in Hebrew, Finnish and even Italian. I want to deprive them of the most obvious excuse for not reading my opus. Like a man I admired, I will first of all thank my wife. In his autobiography, Meir Weisgal, then President of the Weizmann Insti tute of SCience, wrote about his wife: "In addition to her natural endowments - which are considerable - she was a more than competent part-tim~ secretary." He wrote on, and so shall I. The book has been edited by my wife. So if the reader finds the layout pleasant as, in actual fact, I myself do, Birgit is to be praised. If there are blemishes, I am to be blamed for not having caught them.

Lecture Notes in Quantum Chemistry II

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Publisher : Springer Science & Business Media
ISBN 13 : 364257890X
Total Pages : 342 pages
Book Rating : 4.6/5 (425 download)

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Book Synopsis Lecture Notes in Quantum Chemistry II by : Björn O. Roos

Download or read book Lecture Notes in Quantum Chemistry II written by Björn O. Roos and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first volume of Lecture Notes in Quantum Chemistry (Lecture Notes in Chemistry 58, Springer Verlag, Berlin 1992) contained a compilation of selected lectures given at the two first European Summer Schools in Quantum Chemistry (ESQC), held in southern Sweden in August 1989 and 1991, respectively. The notes were written by the teachers at the school and covered a large range of topics in ab initio quantum chemistry. After the third summer school (held in 1993) it was decided to put together a second volume with additional material. Important lecture material was excluded in the first volume and has now been added. Such added topics are: integrals and integral derivatives, SCF theory, coupled-cluster theory, relativity in quantum chemistry, and density functional theory. One chapter in the present volume contains the exercise material used at the summer school and in addition solutions to all the exercises. It is the hope of the authors that the two volumes will find good use in the scientific community as textbooks for students, who are interested in learn ing more about modern methodology in molecular quantum chemistry. The books will be used as teaching material in the European Summer Schools in Quantum Chemistry, which are presently planned. Lund in July 1994 Bjorn Roos NOTES ON HARTREE-FOCK THEORY AND RELATED TOPICS JanAlmlof Department of Chemistry University of Minnesota Minneapolis, MN 55455. USA Contents: 1 • Introduction. 2 . The Born-Oppenheimer Approximation. 3. Determinant Wavefunctions and the Pauli Principle. 4. Expectation Values With a Determinant Wavefunction.

Overlap Determinant Method in the Theory of Pericyclic Reactions

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Publisher : Springer Science & Business Media
ISBN 13 : 3642468179
Total Pages : 135 pages
Book Rating : 4.6/5 (424 download)

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Book Synopsis Overlap Determinant Method in the Theory of Pericyclic Reactions by : Robert Ponec

Download or read book Overlap Determinant Method in the Theory of Pericyclic Reactions written by Robert Ponec and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author summarizes the development and the applications of overlap determinant method in various fields of pericyclic reactivity. The greatest advantage of this new method lies in its remarkable simplicity and flexibility owing to which it opens an interesting possibility of the systematic investigation of important mechanistic problems of pericyclic reactivity which were so far beyond the scope of other existing techniques.

Second-Order Phase Transitions and the Irreducible Representation of Space Groups

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Publisher : Springer Science & Business Media
ISBN 13 : 3642489478
Total Pages : 108 pages
Book Rating : 4.6/5 (424 download)

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Book Synopsis Second-Order Phase Transitions and the Irreducible Representation of Space Groups by : Hugo F. Franzen

Download or read book Second-Order Phase Transitions and the Irreducible Representation of Space Groups written by Hugo F. Franzen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lecture notes presented in this volume were developed over a period of time that originated with the investigation of a research problem, the distortion from NiAs-type to MnP-type, the group-theoretical implications of which were investigated in collaboration with Professors F. Jellinek and C. Haas of the Laboratory for Inorganic Chemistry at the University of Groningen during the 1973-1974 year. This distortion provides the major example that is worked through in the notes. The subject matter of the notes has been incorporated in part in the lectures of a course in Solid State Chemistry taught several times at Iowa State University, and formed the basis of a series of lectures presented at the Max-Planck Institute for Solid State Research in Stuttgart during 1981- 19821 and as part of a Solid State Chemistry course taught during the spring of 1982 at Arizona State University in Tempe. I wish here to express my gratitude to the Max-Planck Institute for Solid State Research and to Arizona State University for the opportunity and support they provided during the time I was developing and writing the lecture notes of this volume. I wish also to thank the many colleagues and students who have offered comments and suggestions that have improved the accuracy and readability of the notes, and who have provided stimulation through discussion of the ideas presented here. am especially indebted to Professors C. Haas and F.

Electrical Double Layer at a Metal-dilute Electrolyte Solution Interface

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Publisher : Springer Science & Business Media
ISBN 13 : 3642487009
Total Pages : 181 pages
Book Rating : 4.6/5 (424 download)

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Book Synopsis Electrical Double Layer at a Metal-dilute Electrolyte Solution Interface by : G.A. Martynov

Download or read book Electrical Double Layer at a Metal-dilute Electrolyte Solution Interface written by G.A. Martynov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the properties of a metal-electrolyte interface, even the spe cific nature of an electrode reaction, proneness of a metal to cor rosion, etc., are primarily determined by the electrical double layer (EDL) at this boundary. It is therefore no surprise that for the last, at least, one hundred years intent attention should have been centered on EDL. So much of material has been gathered to date that we are easi ly lost in this maze of information. A substantial part of the attempts to systematize these facts is made at present within the framework of thermodynamics. Such a confined approach is undoubtedly inadequate. The Gouy-Chapman theory and the Stern-Grahame model of the dense part of EDL developed 40-70 years ago, tailored appropriately to suit the occasion, inevitably underlie any description of EDL. This route is rather too narrow to explain all the facts at our disposal. A dire necessity has thus arisen for widening the principles of the micros copic theory. This is precisely the objective of our monograph. Fur thermore, we shall dwell at length on the comparison of the theory with experiment: without such a comparative analysis, any theory, however elegant it may be, is just an empty drum.