e⁺(PsH)₂: A three-positron molecule with a positronic chemical bond

Area of Science:

• Quantum Chemistry
• Atomic and Molecular Physics
• Positron Interactions

Background:

• Recent discovery of two new positronic molecules: e+H-2 and (PsH)2.
• These molecules are stabilized by a novel 'positronic bond' involving positrons and negative ions.

Purpose of the Study:

• To investigate the possibility of forming a stable molecule with three positrons.
• To characterize the properties of this new three-positron system.

Main Methods:

• Computational investigation of the potential energy curve for the e+(PsH)2 system.
• Analysis of binding energy and equilibrium structure.

Main Results:

• A stable molecular species with three positrons, tentatively named e+(PsH)2, was identified.
• The molecule exhibits an equilibrium structure at approximately 8 bohr.
• A binding energy of 11.5(5) mhartree was calculated with respect to PsH + e+PsH dissociation.

Conclusions:

• The discovery of e+(PsH)2 marks the first observation of a system with three positrons.
• This finding expands the known landscape of positronic molecules and chemical bonding.
• Further research into multi-positron systems is warranted.