Quantum Mechanics 1 starts from the basis that quantum mechanics is of central importance in chemistry. To understand matter and its chemical transformation it is necessary to take a microscopic view connecting experimental observation to the properties of constituent molecules. However, at this microscopic level, atoms and sub-atomic particles do not obey the classical laws of mechanics that pertain to the everyday macroscopic world. They obey the laws of quantum mechanics. This text explains the fundamentals of quantum mechanics from the point of view of chemistry; describes areas of chemistry where quantum mechanics is most important; and shows how quantum mechanics is applied to chemical problems. To this end, the book is divided into two parts: the first deals with the foundations of quantum mechanics (concentrating on exactly soluble problems and the reduction of complicated problems to simple foundations) and the second is a tool kit for applying quantum mechanics to chemical problems (thus concentrating on approximate methods).
Quantum Mechanics 1 starts from the basis that quantum mechanics is of central importance in chemistry. To understand matter and its chemical transformation it is necessary to take a microscopic view connecting experimental observation to the properties of constituent molecules. However, at this microscopic level, atoms and sub-atomic particles do not obey the classical laws of mechanics that pertain to the everyday macroscopic world. They obey the laws of quantum mechanics. This text explains the fundamentals of quantum mechanics from the point of view of chemistry; describes areas of chemistry where quantum mechanics is most important; and shows how quantum mechanics is applied to chemical problems. To this end, the book is divided into two parts: the first deals with the foundations of quantum mechanics (concentrating on exactly soluble problems and the reduction of complicated problems to simple foundations) and the second is a tool kit for applying quantum mechanics to chemical problems (thus concentrating on approximate methods).
Quantum Mechanics 2 opens by stating that the chemist's approach to the understanding of matter and its chemical transformations is to take a microscopic view, connecting experimental observation with the properties of the constituent molecules. Atoms and sub-atomic particles do not obey the classical laws of mechanics but conform rather to the laws of quantum mechanics. Quantum mechanics is thus of central importance in chemistry. In order to understand the behaviour of molecules and their constituent particles it is necessary to have a thorough grounding in the principles and applications of quantum mechanics. This text provides a toolkit for applying quantum mechanics to chemical problems, introducing more advanced approaches using approximate methods. It describes areas of chemistry where quantum mechanics is important, and shows how quantum mechanics can be applied to chemical problems.
This introductory chapter provides an overview of quantum mechanics, which is a subject of central importance in chemistry, and is by nature a mathematical theory. The chemist's approach to the understanding of matter and its chemical transformations is to take a microscopic view, connecting experimental observation with the properties of constituent molecules. However, at the microscopic level, atoms, molecules, and their constituent particles do not obey the familiar laws of mechanics that pertain to the everyday macroscopic world. For example, the existence of molecular line spectra indicates that molecules can be found only at certain well-defined energies, unlike objects at our own scale whose energy appears to be continuously variable. This book aims to explain the fundamentals of quantum mechanics from the point of view of chemistry; describe the areas of chemistry where quantum mechanics is most important; and show how quantum mechanics is applied to chemical problems.
Abstract Of quantum physics, quantum chemistry, and quantum mechanics, the latter is least directly useful for both chemical education and the practice of chemistry as a science concerned with the reactions and properties of chemical substances. We show that quantum mechanics must be viewed as a collection of methods, numbering at least 13, that one might apply to make calculations on a system of an atomic scale. Instead of quantum mechanics, we advocate the quantum laws or laws of discreteness, which have simple roots in laws of conservation and which have practical applications in various areas of observations of chemical phenomena. We conclude that quantum mechanics is largely irrelevant for the general practice of chemistry.
When compared to classical mechanics (CM), quantum mechanics (QM) clearly appears as a difficult topic to the beginner. However, some knowledge of the basics of QM is a real need also for learners with predominant interest in experimental chemistry. Indeed, QM is the physical theory explaining most fundamental aspects of Chemistry, such as the periodic table of the elements and the chemical bond now called covalent, found by 19th century chemists and for a long time recognized as incompatible with the physical theories of the time (CM and classical electromagnetism). Going beyond the historical point of view, many peculiar aspects of QM and its very language permeate all modern chemistry so that a trustworthy understanding is required to deal with the matter in a sensible way.
Quantum mechanics forms the basis of modern physics. In a sense it is the parent theory about which we construct our view of the physical world. Briefly, quantum mechanics is the theory by which we describe the behaviors of subatomic and atomic particles, such as electrons, of which the macroscopic world is made. Although it is not necessary to treat macroscopic objects by use of quantum mechanics, the laws of quantum mechanics and their implications are completely consistent with Newton's Laws of Motion, which we know are applicable to most macroscopic objects. As we will see below, Newton's Laws of Motion are a special subset of quantum mechanics; quantum mechanics reduces to Newton's Laws at macroscopic dimensions. Before we begin our study of quantum mechanics, it is of interest to explain why quantum mechanics is of importance in the study of modern electrical engineering. Many new areas of electrical engineering are based on developments that can be understood only through the use of quantum mechanics. Among these are the broad areas of semiconductors and solid-state electronic devices, electro-optics and lasers, superconductors. It would be fair to say that in the study of each of the above areas some knowledge of quantum mechanics is essential. In this book, some basic concepts in quantum mechanics are presented that are necessary in the study of the above-mentioned disciplines. Introduction The concept most basic toward the understanding of quantum mechanics is the concept of measurement.
Quantum Mechanics is an essential topic in today's physics curriculum at both the undergraduate and graduate levels. Quantum mechanics can explain the microscopic world with fantastic accuracy; the fruits from its insights have created technologies that have revolutionized the world. Computers, lasers, mobile telephones, optical communications are but a few examples. The language of quantum mechanics is now an accepted part of the language of physics and day-to-day usage of this language provides physicists with the intuition that is essential for achieving meaningful results. Nevertheless, most physicists acknowledge that, at least once in their scientific career, they have had difficulties understanding the foundations of quantum theory, perhaps even the impression that a really satisfactory and convincing formulation of the theory is still lacking. Numerous quantum mechanics textbooks are available for explaining quantum formalism and applying it to understand problems such as the properties of atoms, molecules, liquids, and solids; the interactions between matter and radiation; and more generally to understand the physical world that surrounds us. Other texts are available for elucidating the historical development of this discipline and describing the steps through which it went before quantum mechanics reached its modern formulation. In contrast, books are rare that review the conceptual difficulties of the theory and then provide a comprehensive overview of the various attempts to reformulate quantum mechanics in order to solve these difficulties. The present text by Franck Laloë does precisely this.