Photoabsorption spectra of small mercury clusters: a computational study

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Atomic and Molecular Physics

Background:

• Understanding the electronic and optical properties of small clusters is crucial for materials science.
• Mercury-nitrogen (HgN) clusters represent a system with potential applications, yet their photoabsorption spectra are not fully characterized.
• Previous studies may lack detailed theoretical calculations covering a range of temperatures and quantum effects.

Purpose of the Study:

• To calculate the photoabsorption spectra of small mercury-nitrogen (HgN) clusters (N=2-5).
• To provide absorption cross-sections across a broad range of photon energies (4.0-7.5 eV).
• To investigate the influence of temperature and quantum delocalization on the spectra.

Main Methods:

• Employed a diatomics-in-molecules (DIM) interaction model for cluster calculations.
• Utilized an atoms-in-molecules (AIM) approach for transition probability calculations.
• Incorporated quantum and temperature-induced nuclear delocalization using classical and path-integral Monte Carlo methods, and vibrational wavefunction sampling.

Main Results:

• Calculated photoabsorption spectra for HgN clusters (N=2-5) from 4.0 to 7.5 eV.
• Quantified absorption cross-sections considering temperatures from 0 K to 40 K.
• Demonstrated the impact of nuclear delocalization on spectral features.

Conclusions:

• The theoretical calculations provide a comprehensive dataset for HgN cluster photoabsorption.
• The study offers a valuable comparison between theoretical predictions and available experimental data.
• This work enhances the understanding of electronic transitions and structural dynamics in small mercury-nitrogen clusters.