ABSTRACT
Fundamental to all properties is the basic electronic structure, i.e., the eigenvalues, the nature of the energy spectrum, the charge and spin densities, the molecular orbitals or the Bloch states, the density of states, the energy gaps, etc. of the interacting electrons. It is natural to expect the electronic structure to change signi cantly if the dimensionality is reduced. is is best illustrated by examining the density of states, a property o en studied. e density of states tells us the number of energy states available within a small energy interval. In Figure 18.1, we show the density of states for the materials with di erent dimensionalities within the free electron approximation. e model systems are shown on top of the density of states.
