Spin-Crossover from a Well-Behaved, Low-Cost meta-GGA Density Functional.

Area of Science:

• Computational chemistry
• Quantum mechanics
• Materials science

Background:

• The accuracy of meta-generalized gradient approximation (meta-GGA) functionals is crucial for predicting electronic properties.
• Spin-crossover phenomena are important in transition metal complexes and materials.

Purpose of the Study:

• To evaluate the performance of the modified r2SCAN meta-GGA functional for calculating spin-crossover electronic energies.
• To compare r2SCAN with the original SCAN functional and its deorbitalized variant, r2SCAN-L.

Main Methods:

• Utilized a benchmark dataset of spin-crossover systems.
• Calculated high spin minus low spin electronic energies using r2SCAN and r2SCAN-L.
• Assessed computational speed for periodically bounded systems.

Main Results:

• r2SCAN demonstrated significantly improved accuracy for spin-crossover energies compared to SCAN.
• r2SCAN-L showed comparable accuracy to SCAN but with considerably faster computation times in periodic systems.
• Both functionals showed good performance on iron complexes.

Conclusions:

• r2SCAN is a promising advancement for accurate spin-crossover energy calculations.
• r2SCAN-L offers a computationally efficient alternative for periodic systems.
• A combined strategy is recommended for balanced treatment of molecular and periodic spin-crossover systems.