The ab initio density functional theory applied for spin-polarized calculations.

Area of Science:

• Quantum Chemistry
• Computational Physics
• Theoretical Chemistry

Background:

• Accurate prediction of molecular properties is crucial in chemistry and materials science.
• Developing reliable computational methods is essential for understanding chemical reactions and molecular behavior.
• Spin-polarized systems present unique challenges in electronic structure calculations.

Purpose of the Study:

• To systematically evaluate the performance of the ab initio OEP2-sc functional.
• To assess its accuracy for spin-polarized systems, including ionization potentials and energies.
• To compare OEP2-sc with other established computational methods like orbital-optimized MP2.

Main Methods:

• Ab initio calculations using the OEP2-sc functional.
• Computation of ionization potentials for various molecules.
• Calculation of atomization and reaction energies for closed- and open-shell systems.
• Comparative analysis against the orbital-optimized MP2 method.

Main Results:

• OEP2-sc demonstrates accurate performance for spin-polarized systems.
• Results are competitive with the orbital-optimized MP2 method.
• The functional's accuracy is not attributed to error cancellation, unlike double-hybrid functionals.

Conclusions:

• The OEP2-sc functional is a reliable and accurate method for studying spin-polarized systems.
• Its performance makes it a viable alternative to existing methods for electronic structure calculations.
• The inherent accuracy of OEP2-sc offers a robust approach without relying on error compensation mechanisms.