Полнотекстовый поиск:
Где искать:
только в названии
только в тексте
слова в тексте
только заголовок

Рекомендуем ознакомиться

Остальные работы->Реферат
Statistics on an issue such as gun control are not hard to come by. The numbers seem to sway in the favor of gun control being ineffective against the...полностью>>
Остальные работы->Реферат
Sometimes a situation in a play can be repeated in another play can be repeated in another play but receive a different reaction and/or outcome. In th...полностью>>
Остальные работы->Реферат
Every day we look out upon the night sky, wondering and dreaming of what lies beyond our planet. The universe that we live in is so diverse and unique...полностью>>
Остальные работы->Реферат
Love: What is it? To many people love means many things. To others, to love is to place their happiness in one another. Love can be how they feel abou...полностью>>

Главная > Реферат >Остальные работы

Сохрани ссылку в одной из сетей:

The molecular structure hypothesis – that a molecule is a collection of atoms linked by a network of bonds – was forged in the crucible of nineteenth century experimental chemistry. It has continued to serve as the principal means of ordering and classifying the observations of chemistry. The difficulty with this hypothesis was that it was not related directly to quantum mechanics, the physics which governs the motions of the nuclei and electrons that make up the atoms and the bonds. Indeed there was, and with some there still is, a prevailing opinion that these fundamental concepts, while unquestionably useful, were beyond theoretical definition. We have in chemistry an understanding based on a classification scheme that is both powerful and at the same time, because of its empirical nature, limited.

Richard Feynman and Julian Schwinger have given us a reformulation of physics that enables one to pose and answer the questions “what is an atom in a molecule and how does one predict its properties?” These questions were posed in my laboratory where it was demonstrated that this new formulation of physics, when applied to the observed topology of the distribution of electronic charge in real space, yields a unique partitioning of some total system into a set of bounded spatial regions. The form and properties of the groups so defined faithfully recover the characteristics ascribed to the atoms and functional groups of chemistry. By establishing this association, the molecular structure hypothesis is freed from its empirical constraints and the full predictive power of quantum mechanics can be incorporated into the resulting theory – a theory of atoms in molecules and crystals.

The theory recovers the central operational concepts of the molecular structure hypothesis, that of a functional grouping of atoms with an additive and characteristic set of properties, together with a definition of the bonds that link the atoms and impart the structure. Not only does the theory thereby quantify and provide the physical understanding of the existing concepts of chemistry, it makes possible new applications of theory. These new applications will eventually enable one to perform on a computer, in a manner directly paralleling experiment, everything that can now be done in the laboratory, but more quickly and more efficiently, by linking together the functional groups of theory. These applications include the design and synthesis of new molecules and new materials with specific desirable properties.

The theory of atoms in molecules enables one to take advantage of the single most important observation of chemistry, that of a functional group with a characteristic set of properties. This document outlines and illustrates the topological basis of the theory and its relation to the quantum mechanics of an open system.

Загрузить файл

Похожие страницы:

  1. The Ozone Layer Essay Research Paper The

    Реферат >> Остальные работы
    ... follows, will discuss the structure of the ozone layer, so that ... it is required atomic chlorine. The molecular chlorine is split ... is not only a choice research, but also a necessary ... propane into the Antarctic stratosphere each spring. The chemicals would ...
  2. Isomers Essay Research Paper 32 Lots of

    Реферат >> Остальные работы
    Isomers Essay, Research Paper 3.2 Lots of carbon compounds seem ... as structural isomers, which have the same number of atoms of each element and molecular ... above the plane of the paper, the central carbon atom in the plane of the paper, and the ...
  3. Nano Technology Essay Research Paper Nanotechnlogy18 seems

    Реферат >> Остальные работы
    Nano Technology Essay, Research Paper Nanotechnlogy 18 seems to be the magic number in today ... engineering called molecular nanotechnology (MNT). If we can place atoms on a structure under ...
  4. Combustion Of Alcohols Essay Research Paper Comparing

    Реферат >> Остальные работы
    Combustion Of Alcohols Essay, Research Paper Comparing Energy Release from the Combustion of Alcohols I am ... , where n is the number of Carbon atoms. The similarities in molecular structure make alcohols have ...
  5. Nanotechnology Essay Research Paper Curtis Shephard Nanotechnology

    Реферат >> Остальные работы
    Nanotechnology Essay, Research Paper Curtis Shephard Nanotechnology: Immortality or ... at the molecular level, but it can pick up and move atoms as ... materials and structures (Dowie 5). Another perceived nanomachine is the assembler. The assembler is ...

Хочу больше похожих работ...

Generated in 0.0010628700256348