  A tendency to form benzene-like molecular orbitals has been recently shown to
be a common feature of the $4d$ and $5d$ transition metal oxides with a
honeycomb lattice. This tendency competes with other interactions such as the
spin-orbit coupling and Hubbard correlations, and can be partially or
completely suppressed. In the calculations, SrRu$_{2}$O$_{6}$ presents the
cleanest, so far, case of well-formed molecular orbitals, however, direct
experimental evidence for or against this proposition has been missing. In this
paper, we show that combined photoemission and optical studies can be used to
identify molecular orbitals in SrRu$_{2}$O$_{6}$. Symmetry-driven election
selection rules suppress optical transitions between certain molecular
orbitals, while photoemission and inverse photoemission measurements are
insensitive to them. Comparing the photoemission and optical conductivity
spectra one should be able to observe clear signatures of molecular orbitals.
