Chemistry Reference
In-Depth Information
Figure 1.26. Details of the stacking of (a)
α
-CuPc (crystallographic data from
Hoshino
et al.
, 2003) and (b)
-CuPc (crystallographic data as supplied by the
Cambridge Crystallographic Data Centre). C atoms are represented by black balls.
β
relations, that is energy
E
as a function of the wave vector
k
:
E
(
k
). Chemists,
however, try to retain the orbital and bond signatures to the band structure. In the
case of MOMs the chemists' approach seems more appropriate since MOs are only
slightly perturbed by the formation of the solid, hence the electronic origin of the
band can be unambiguously described in terms of MOs. This is the reason for the
sometimes confusing assignation of point groups to bands, which should strictly
be classified according to the space group. In what follows we try to set a common
theoretical ground, based on the minimum required quantum-mechanical concepts,
to describe the electronic structure of molecules and solids. In spite of the simplicity
of the model, several fundamental concepts applicable to MOMs will be derived,
so let me suggest, in particular to those not familiar with the field, a careful reading
of this section.
