A path integral molecular dynamics study on the muoniated xanthene-thione molecule

Area of Science:

• Computational Chemistry
• Quantum Mechanics
• Spectroscopy

Background:

• Muonium (Mu) is crucial for studying radical species' spin density.
• Theoretical calculations require accounting for quantum effects due to muonium's light mass.

Purpose of the Study:

• To investigate the quantum mechanical behavior of muonium in 9H-xanthene-9-thione (μXT).
• To accurately estimate the hyperfine coupling constant (HFCC) of muoniated species.

Main Methods:

• Utilized ab initio path integral molecular dynamics (PIMD) simulations.
• Incorporated multi-dimensional quantum effects for muonium.

Main Results:

• Quantum effects significantly increased the HFCC value of μXT.
• Observed a longer S-Mu bond length in μXT compared to S-H in HXT.
• Identified a preferred perpendicular orientation of the S-Mu bond relative to the molecular plane.

Conclusions:

• PIMD simulations qualitatively improved HFCC calculations for μXT.
• Quantum effects and structural preferences enhance spin density transfer to muonium, increasing HFCC.