Electronic excitations in 5d4J=0Os4+ halides studied by resonant inelastic x-ray scattering and …

The cubic halides K${}_{2}$OsCl${}_{6}$, K${}_{2}$OsBr${}_{6}$, and Rb${}_{2}$OsBr${}_{6}$ are found to be excellent realizations of spin-orbit-entangled nonmagnetic $J$=0 compounds in the intermediate coupling regime. The two complementary techniques of resonant inelastic x-ray scattering and optical spectroscopy allow the authors to draw a comprehensive picture of the electronic excitations and to assess the electronic structure. The accurate set of electronic parameters such as spin-orbit coupling, Hund's coupling, crystal-field splitting, Mott gap, and charge-transfer energy will serve as a solid reference for future studies on Os compounds.