Multipolar propagators near a small metallic sphere: A self-consistent calculation

The response field of a small metallic sphere to fluctuating dipole and quadrupole moments is built from the spherical tensor theory. This field is then used to define various dipolar and quadrupolar propagators between two points outside the sphere. The nonlocal character of the electron's response inside the sphere is included through a self consistent method and the metallic ions are schematized by a jellium model. We show that the spherical tensors formalism provides a good basis for a simple formulation of the successive field gradient susceptibility (a)S(á) near a spherical surface. The dipolar contribution of the van der Waals energy between a rare gas atom and a metallic sphere is given as an application of the method. Consistency with other approaches is also examined.