Two-Positron-bonded Dihalides: Ps₂XY (X, Y=F, Cl, Br)

Area of Science:

• Quantum Chemistry
• Computational Physics
• Materials Science

Background:

• Positron-bound molecules offer a unique avenue for exploring chemical bonding.
• Understanding the stability and properties of these exotic systems is crucial for advancing quantum chemistry.

Purpose of the Study:

• To investigate the energetic stability and physical characteristics of two-positron halide complexes (PsXY⁻).
• To analyze the nature of two-positron bonding and compare it with existing molecular systems.
• To explore the relationship between positron-bound dihalides and their electron-bound dialkali analogs.

Main Methods:

• Utilized high-level electronic coupled cluster (CCSD(T)) calculations.
• Employed positronic multicomponent renormalized partial third-order propagator (MC-REN-PP3) methods.
• Analyzed potential energy curves, electron, and positron densities.

Main Results:

• Confirmed the energetic stability and identified global minima for $$ complexes.
• Demonstrated stabilization through the formation of two-positron bonds.
• Observed shorter bond lengths, higher force constants, and greater bond energies in $$ compared to isoelectronic dialkali molecules.

Conclusions:

• The study establishes the existence and stability of novel two-positron halide molecules.
• Positron bonding in $$ systems exhibits unique characteristics and periodic trends analogous to electron bonding.
• These findings open new perspectives in the study of exotic matter and chemical bonding.