Density functional study of structure and dynamics in liquid antimony and Sb_n clusters

Area of Science:

• Computational materials science
• Condensed matter physics
• Quantum chemistry

Background:

• Antimony (Sb) is a pnictogen element with unique electronic and structural properties.
• Understanding the behavior of liquid metals and clusters is crucial for materials science and chemical applications.
• Previous studies have explored bismuth (Bi) aggregates, providing a basis for comparison.

Purpose of the Study:

• To investigate the structural and dynamical properties of liquid antimony and neutral Sb clusters using simulations.
• To analyze the effects of temperature on the liquid state of antimony.
• To compare the behavior of antimony with that of bismuth.

Main Methods:

• Density functional theory (DFT) and molecular dynamics (MD) simulations were employed.
• Simulations were conducted on liquid antimony (588 atoms) across six temperatures (600 K to 1300 K).
• Neutral Sb clusters containing up to 14 atoms were also simulated.

Main Results:

• Analysis of coordination numbers, bond angles, ring patterns, structure factors, and pair distribution functions revealed key structural characteristics.
• Dynamical properties, including vibration frequencies, diffusion constants, power spectra, dynamical structure factors, and viscosity, were computed.
• Higher temperatures in liquid antimony resulted in broader bond angle distributions, increased cavity volumes, and reduced correlations between bond lengths.

Conclusions:

• The study identified three short covalent bonds as characteristic of pnictogen clusters.
• Similarities in structural and dynamical properties were observed between antimony and bismuth aggregates.
• Simulation results provide valuable data for understanding the condensed phases of antimony.