In this project electronic excitations of small metal
clusters by weak laser fields have been studied , i.e. the dynamical
response properties of the clusters within the linear regime.
Due to the high sensitivity of the photo-absorption cross sections to
both the geometrical structure of the clusters and
exchange-correlation(xc)-effects there has
been some controversy in the literature regarding the origin of differences
between theory and experiment. As neither the cluster structure nor the
xc-effects can be treated exactly, the deficiencies of approximations
employed for the treatment of one effect tend to obsure the outcomes of the
other and vice versa.
In the present work  only the role of xc-effects has been investigated.
The influence of geometry has been completely neglected by using the
structureless spherical jellium model.
It has been the aim of this study to gain a better understanding of the
validity of approximations to the xc-potential, which have recently been
employed in time-dependent density functional
calculations of photo-absorption cross sections.