Beyond electronic stabilization: towards a multicomponent conceptual density-functional theory for positron-driven...

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Multicomponent Systems

Background:

• Conventional bonding theory links stability to electronic energy lowering.
• This model may not apply to systems with additional quantum particles.
• Existing theories struggle with multicomponent quantum stability.

Purpose of the Study:

• To extend conceptual DFT to multicomponent quantum systems.
• To develop a framework for analyzing bonding in systems with multiple particle species.
• To generalize bonding criteria beyond electronic contributions.

Main Methods:

• Constructed a multicomponent conceptual density-functional theory (MC-CDFT).
• Utilized a constrained-search formulation for multicomponent energy functionals.
• Generalized DFT descriptors to species-resolved vectors and matrices encoding intercomponent coupling.

Main Results:

• Bonding is governed by the curvature of the total multicomponent energy functional.
• Intercomponent coupling can stabilize systems even with destabilizing electronic contributions.
• Demonstrated this mechanism with Quantum Monte Carlo results for e+:Be2 complex.

Conclusions:

• MC-CDFT provides a new perspective on bonding in multicomponent quantum systems.
• Stability criteria must account for intercomponent coupling, not just electronic energy.
• The framework offers a general approach to understanding complex quantum system stability.