A molecular model potential study of the HOMO-LUMO gap in a low-dimensional crystal
We study the effect of some crystal vibrations on the electron distribution and the gap HOMO-LUMO in a linear chain of atoms where, the valence electrons move in a model potential constructed by combining atromic boxes. It is found that at the turning points, these two levels collapse together for a chain with an even number of atoms while for a chain with an odd number of atoms these two levels never touch each other. The effect of some asymmetric crystal vibrations on the electron density distribution and the gap HOMO-LUMO is also analyzed for a low-dimensional solid whose repeating unit consists of a square arrangement of atoms where the valence electrons move in a CAB model potential.
model potentials low-dimensional solids conducting gap