Snowballs, quantum solvation and coordination: lead ions inside small helium droplets

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Atomic and Molecular Physics

Background:

• Understanding the behavior of doped helium clusters is crucial for various applications.
• Lead ions (Pb2+ and Pb+) provide a unique system to study solvation effects due to their electronic structure.

Purpose of the Study:

• To develop an accurate analytical many-body potential for Pb(2+)He(n) and Pb(+)He(n) clusters.
• To investigate the impact of quantum effects on the formation of solvation shells in these clusters.

Main Methods:

• Ab initio calculations were employed to construct the many-body potential.
• Diffusion quantum Monte Carlo calculations were used to determine ground state energies and structures.

Main Results:

• The potential accurately reproduces global minima for cluster sizes up to n=16.
• For Pb(2+)He(n), a first solvation shell closes at n=12, with a second shell forming at n=16.
• Spin-orbit coupling significantly affects Pb(+)He(n) structures, leading to gradual evolution without distinct shells.

Conclusions:

• The developed potential enables accurate modeling of Pb-He cluster properties.
• Quantum effects play a significant role in the solvation shell formation.
• The distinct structural behaviors of Pb(2+) and Pb+ in helium environments are highlighted.