Revisiting the role of octahedral symmetry in the interpretation of spectroscopic properties of [OsF 6 ] 2- and PtF 6 complexes.

The electronic structure of [OsF 6 ] 2- and PtF 6 complexes was studied by means of CASSCF/NEVPT2 multiconfigurational calculations, including spin-orbital coupling, which is very relevant in the case of these metals. From these calculations, it is possible to establish that in the octahedral symmetry ( O h ), the ground state is non-magnetic ( J eff = 0) because of the strong ligand field, and the interaction with paramagnetic excited states is almost negligible, resulting in a non-magnetic behavior, which is in agreement with the experimental evidence.