  The influence of morphology on the optical properties of silver nanoparticles
is studied. A general relationship between the surface plasmon resonances and
the morphology of each nanoparticle is established. The optical response is
investigated for cubes and decahedrons with different truncations. We found
that polyhedral nanoparticles composed with less faces show more surface
plasmon resonances than spherical-like ones. It is also observed that the
vertices of the nanoparticles play an important role in the optical response,
because the sharpener they become, the greater the number of resonances. For
all the nanoparticles, a main resonance with a dipolar character was identified
as well as other secondary resonances of less intensity. It is also found that
as the nanoparticle becomes more symmetric, the main resonance is always blue
shifted.
