  Orbital degrees of freedom play a major role in the physics of many strongly
correlated transition metal compounds. However, they are still very difficult
to access experimentally, in particular by neutron scattering. We propose here
how to reveal orbital occupancies of the system ground state by magnetic
resonant inelastic x-ray scattering (RIXS). This is possible because, unlike in
neutron scattering, the intensity of the magnetic excitations in RIXS depends
essentially on the symmetry of the orbitals where the spins are in.
