ABSTRACT
Energy is what makes crystal binding possible. In this regard, two kinds of energy terms are in general use to describe the binding energy. One is the cohesive energycohesive energy and the other is the lattice energylattice energy. This chapter develops a potential that is commonly used to understand ionic systems. The potential minimum is the lattice energylattice energy of the crystal system. The chapter deals with the hydrogen molecule and presents a fully numeric calculation of its bonding and antibonding states based on the simplest wavefunction possible. The Madelung energy helps us to do a better accounting for the interactions between a given ion and the rest of the ions of an ionic crystal. The bonding that takes place leads to the creation of stable molecules and crystals. Covalent bonding is most easily understood in terms of a simple quantum mechanical model of a molecule in which electrons are shared among the protons.
