Applications and Extension of the Theory of Atoms in Molecules

Abstract

<p>This thesis applies and extends the theory of atoms in molecules. The charge distributions of diatomic molecules, hydrocarbons, hydrogen-bonded complexes and complexes containing NN bonds are examined.</p> <p>The theory of atoms in molecules provides a quantum mechanical definition of an atom in a molecule and its properties. The topology of the charge distribution is the observational basis for the elements of molecular structure, structural change and stability.</p> <p>The theory is reviewed in Chapter 1. Studies of hydrocarbons and diatomic molecules are made and the new concept of atomic valume is introduced. Electronegativity schemes are explored and extended.</p> <p>The nature of the hydrogen bond is discussed in Chapter 2. The charge redistribution which allows for mutual penetration of the van der Waals envelopes of the base atom and the H-bonded H atom is investigated.</p> <p>Chapter 3 shows how the Laplacian of the charge density can be used to predict structures and geometries of hydrogen-bonded complexes. Reactivities of activated double bonds to nucleophilic attack are predicted.</p> <p>Chapter 4 surverys a set of complexes containing NN bonds and proposes a bond order and bond energy scheme for these bonds.</p> <p>Chapter 5 uses density functional theory to construct correlation energy functionals. The correlation energies of atoms in molecules can then be studied and total energies of molecules calculated.</p>