Real-space multiple-scattering Hubbard model calculations for d- and f-state materials

Area of Science:

• Condensed matter physics
• Materials science
• Computational chemistry

Background:

• Correlated d- and f-electron states significantly influence material properties.
• Accurate theoretical models are needed to understand these complex electronic systems.
• X-ray spectroscopy is a key experimental technique for probing electronic structure.

Purpose of the Study:

• To develop and apply an efficient computational method for calculating electronic structure and X-ray spectra.
• To investigate the effects of correlated electron states on core-level X-ray spectra.
• To provide theoretical predictions for transition metal- and lanthanide-oxides.

Main Methods:

• Hubbard model combined with real-space multiple-scattering formalism.
• Rotationally invariant local density approximation.
• Ab initio calculation of Hubbard parameter using constrained random-phase approximation.
• Real-space Green's function approach.

Main Results:

• Calculated electronic structure and X-ray spectra for correlated electron materials.
• Accurate determination of Hubbard parameter values.
• Demonstrated efficiency in describing localized correlated electron states.
• Projected density of states and X-ray absorption spectra for transition metal- and lanthanide-oxides.

Conclusions:

• The combined real-space Green's function and Hubbard model approach is effective for studying correlated electron systems.
• The method provides results in good agreement with experimental data.
• This work offers a valuable tool for predicting and understanding the properties of complex oxides.