Polonium: Structural Evolution, Electronic Properties, and Decay Dynamics Simulation at Cluster Size.

Area of Science:

• Physical Chemistry
• Materials Science
• Nuclear Chemistry

Background:

• Polonium (Po) is unique for forming a simple cubic lattice.
• The structural configurations and electronic properties of polonium clusters remain understudied.
• Understanding these properties is crucial for insights into Group VIA and radioactive clusters.

Purpose of the Study:

• To determine the low-energy structures and isomers of polonium clusters (Po_n^0/-, n=3-18).
• To investigate the electronic properties and stability of polonium clusters.
• To compare polonium cluster behavior with other Group VIA elements.

Main Methods:

• CALYPSO method for structure prediction.
• Density Functional Theory (DFT) for electronic structure calculations.
• Analysis of Molecular Orbitals (MOs) and Atoms in Molecules (AIM) analysis.

Main Results:

• Ground-state geometries and most isomers of polonium clusters are cyclic.
• A highly stable, symmetric (D_4d) crown-ring structure was identified for the Po8 cluster.
• Hybridization of the 6p orbital and π-bond formation are key to the crown-ring structure.
• Polonium cluster dissociation rates are comparable to ²¹⁰Po decay rates.
• Recoil energy effects on potential energy during decay were simulated.

Conclusions:

• Polonium clusters exhibit predominantly cyclic structures, with Po8 being a notable stable crown-ring example.
• The electronic structure, particularly 6p orbital hybridization and π-bonding, dictates the stability of these cyclic configurations.
• The study provides a foundation for understanding the behavior of radioactive clusters and their decay dynamics.