Crystal field excitation

Crystal field excitation is the electronic transition of an electron between two orbitals of an atom that is situated in a crystal field environment.^[1] They are often observed in coordination complexes of transition metals.^[2] Some examples of crystal field excitations are dd-transitions on a copper atom that is surrounded by an octahedron of oxygen atoms, or ff-transitions on the uranium atom in uranium antimonide.^[3]