Performance of the r²SCAN Functional in Transition Metal Oxides

Area of Science:

• Computational Materials Science
• Condensed Matter Physics
• Quantum Chemistry

Background:

• Transition metal oxides (TMOs) exhibit complex electronic properties crucial for various applications.
• Accurate theoretical prediction of TMO properties requires robust and computationally efficient electronic structure methods.
• Existing functionals like SCAN have limitations in describing TMOs, necessitating advanced approximations.

Purpose of the Study:

• To evaluate the accuracy and computational efficiency of the novel r²SCAN meta-generalized gradient approximation (metaGGA) functional for TMO systems.
• To compare the performance of r²SCAN against the SCAN functional, including investigations with Hubbard U corrections (r²SCAN+U and SCAN+U).
• To assess the transferability of optimal Hubbard U values for transition metals in various TMOs.

Main Methods:

• Benchmarking r²SCAN and SCAN functionals against experimental and calculated data for oxidation enthalpies, lattice parameters, magnetic moments, and band gaps of binary 3d TMOs.
• Systematic evaluation of Hubbard U corrections for transition metals to optimize r²SCAN accuracy.
• Verification of U-correction transferability across different TMOs.

Main Results:

• r²SCAN (+U) demonstrates improved accuracy in describing ground-state properties of TMOs compared to SCAN (+U).
• r²SCAN (+U) calculations show marginally larger lattice parameters, smaller magnetic moments, and lower band gaps than SCAN (+U).
• The r²SCAN (+U) framework exhibits superior computational efficiency over SCAN (+U).

Conclusions:

• The r²SCAN functional, with or without U-correction, provides a more accurate and computationally efficient approach for studying TMOs.
• r²SCAN (+U) offers a promising framework for reliable prediction of TMO properties, advancing materials discovery.
• The findings suggest r²SCAN as a valuable tool for theoretical investigations in condensed matter physics and materials science.