A spectroscopic case for SPSi detection: The third-row in a single molecule

Area of Science:

• Astrochemistry
• Computational Chemistry
• Spectroscopy

Background:

• Sulfur, phosphorus, and silicon chemistry are vital for understanding astronomical and atmospheric molecules beyond the second row of the periodic table.
• Silicon's abundance in astrophysical environments and rocky bodies makes its compounds significant.
• Triatomic molecules of these elements are key targets for spectroscopic characterization and studying non-carbon-based chemistry.

Purpose of the Study:

• To investigate the fundamental properties of the simplest heterogeneous third-row triatomic molecules.
• To provide new insights into the chemical physics of these systems using advanced computational methods.
• To generate spectroscopic data for laboratory and observational astronomy.

Main Methods:

• High-level quantum chemical techniques were employed.
• Calculations focused on fundamental vibrational frequencies, rotational constants, and excited state properties.
• Isotopic substitution effects were also considered.

Main Results:

• Fundamental vibrational frequencies were found to be in the 350-600 cm⁻¹ range.
• The molecules exhibited minimal anharmonicity.
• Comprehensive spectroscopic data, including rotational constants and excited state information, were generated.

Conclusions:

• The calculated spectroscopic data will assist laboratory experiments and telescopic observations.
• This work enhances our understanding of silicon, sulfur, and phosphorus chemistry in astrophysical contexts.
• The findings contribute to the characterization of non-carbon-based molecules relevant to space and Earth's atmosphere.