  Magnetic adsorbates on superconductors induce local bound states within the
superconducting gap. These Yu-Shiba-Rusinov (\YSR) states decay slowly away
from the impurity compared to atomic orbitals, even in 3d bulk crystals. Here,
we use scanning tunneling spectroscopy to investigate their hybridization
between two nearby magnetic Mn adatoms on a superconducting Pb(001) surface. We
observe that the hybridization leads to the formation of symmetric and
antisymmetric combinations of \YSR states. We investigate how the structure of
the dimer wave functions and the energy splitting depend on the shape of the
underlying monomer orbitals and the orientation of the dimer with respect to
the Pb lattice.
