2026/03/03 by Anonymous, Teruki Matsuzaki, Liviu F. Chibotaru +2
Physics and Astronomy · Materials Science · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Magnetism in coordination complexes
paper · pdf · doi:10.1103/j2fd-szjx
First-principles analysis of the spectroscopic signatures of correlated quantum materials poses significant challenges due to the interplay between spin-orbit and vibronic couplings, as well as the need to describe both dynamic and static electron correlation to reach decent accuracy. In this work, we apply the equation-of-motion coupled-cluster (EOM-CC) method to derive the spin-orbit-lattice entangled vibronic states and predict the Re L3 edge resonant inelastic x-ray scattering (RIXS) spectra of Ba2MgReO6. The EOM-CC yields interaction parameters in close agreement with those extracted from RIXS spectra, with errors of less than 5%. In particular, the EOM-CC method allowed us to determine the weak vibronic coupling to the T2g vibrations, which is difficult to address experimentally. The simulated spectra indicate that vibronic coupling to the T2g modes gives rise to a shoulder on the elastic peak. Going beyond the conventional treatment, which focuses solely on Eg modes, we show that vibronic couplings to both T2g and Eg modes are required to account for the fine structure of the RIXS spectra. This work demonstrates that the EOM-CC method is a powerful tool for accurately predicting the complex local states at metal sites and spectroscopic signatures of correlated insulating materials.