A new all-round density functional based on spin states and S(N)2 barriers

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Materials Science

Background:

• Existing density functionals like OPBE and PBE have limitations in accurately describing electronic properties.
• Previous work introduced the SSB-sw functional by switching between OPBE and PBE to balance performance for spin states, reaction barriers, and weak interactions.

Purpose of the Study:

• To develop an improved empirical density functional (SSB-D) for enhanced accuracy in computational chemistry.
• To refine the SSB-sw functional by incorporating the KT functional and Grimme's dispersion correction.
• To evaluate the performance of the new SSB-D functional for biological applications.

Main Methods:

• Construction of a new empirical density functional (SSB-D) based on OPBE and PBE.
• Inclusion of the KT functional and Grimme's dispersion correction for pi-pi stacking.
• Assessment of the functional's performance for spin states, S(N)2 reaction barriers, weak interactions, and biological systems.

Main Results:

• The SSB-D functional demonstrates improved performance compared to previous functionals.
• Accurate predictions for hydrogen bonding, pi-pi stacking, and spin-state splittings.
• High accuracy in geometries and reaction barriers relevant to biological systems.

Conclusions:

• The developed SSB-D functional represents a significant advancement in density functional theory.
• SSB-D offers a robust tool for studying complex biological systems computationally.
• The functional provides a balanced and accurate description of various chemical interactions.