  The van der Waals potential of two atoms in the presence of an arbitrary
arrangement of dispersing and absorbing magnetodielectric bodies is studied.
Starting from a polarizable atom placed within a given geometry, its
interaction with a second polarizable/magnetizable atom is deduced from its
Casimir-Polder interaction with a weakly polarizable/magnetizable test body.
The general expressions for the van der Waals potential hence obtained are
illustrated by considering first the case of two atoms in free space, with
special emphasis on the interaction between (i) two polarizable atoms and (ii)
a polarizable and a magnetizable atom. Furthermore, the influence of
magnetodielectric bodies on the van der Waals interaction is studied in detail
for the example of two atoms placed near a perfectly reflecting plate or a
magnetodielectric half space, respectively.
