Molecular orbitals

Abstract

This chapter studies the electronic wavefunction, which determines the distribution of electrons in the molecule, and therefore the bonding. Chemists describe bonding in terms of atomic and molecular orbitals, and the chapter shows how group theory can be used to classify the symmetries of orbitals and to find suitable combinations of atomic orbitals for the construction of a molecular orbital. It begins by considering the case of atoms before proceeding to the more complex problem of molecules. In the orbital approximation, the electronic wavefunction of an atom is constructed as a product of one-electron wavefunctions, or orbitals. Each orbital obeys a Schrödinger equation. The chapter then looks at the linear combination of atomic orbitals (LCAO) method; π bonding; and orbital symmetry and chemical reactivity.