“…The calculated electronic energies of all the relevant states of UO 2 2+ plus the corresponding transition dipole moments 73 are used to calculate the RIXS spectra using the Kramers–Heisenberg formula. 11 , 21 , 22 , 24 , 30 , 31 The polarizability tensor reads 24
with the resonance scattering cross-section as follows
μ, ρ = x , y , z : ( x , y , z ) component of the electric–dipole transition operator; |0⟩, E 0 : ground state (3d 10 4f 14 5f 0 ) and corresponding energy; | i ⟩, E i : intermediate states (3d 9 4f 14 5f 1 ) and corresponding energy; | f ⟩, E f : final states (3d 10 4f 13 5f 1 ) and corresponding energy; E ex : excitation energy, E ex = E i – E 0 ; E em : emission energy, E ex = E i – E f ; Γ i : line broadening due to the lifetime of the intermediate states; and Γ f : line broadening due to the lifetime of the final states.…”