Multi-orbital cluster perturbation theory for transition metal oxides

Area of Science:

• Condensed matter physics
• Quantum chemistry
• Materials science

Background:

• Understanding electron-electron (e-e) repulsion is crucial for describing correlated materials.
• Existing theories may struggle with the complexity of real materials containing diverse atomic species and orbitals.

Purpose of the Study:

• To extend cluster perturbation theory (CPT) to incorporate many-body correlations from local e-e repulsion.
• To demonstrate the capability of the extended CPT to model complex correlated materials.

Main Methods:

• Developed an extension of cluster perturbation theory.
• Incorporated many-body correlations due to local e-e repulsion.
• Applied the method to the prototypical case of manganese oxide (MnO).

Main Results:

• The extended CPT successfully includes many-body correlations from local e-e repulsion.
• The approach accurately describes the physics of complex correlated materials.
• Demonstrated applicability to materials with coexisting atomic species and orbitals, using MnO as an example.

Conclusions:

• The enhanced cluster perturbation theory provides a robust framework for studying complex correlated materials.
• This method offers a way to accurately model the intricate electronic correlations in real materials.