Vibrational analyses for CHFClBr and CDFClBr based on high level ab initio calculations

Area of Science:

• Quantum Chemistry
• Molecular Spectroscopy
• Computational Chemistry

Background:

• Accurate prediction of molecular vibrational spectra is crucial for understanding molecular properties and interactions.
• Chiral molecules like CHFClBr are of interest for fundamental physics, including parity-violation studies.

Purpose of the Study:

• To compute anharmonicity corrections to the harmonic vibrational spectra of CHFClBr and its deuterated isotopomer.
• To compare the accuracy of variational and perturbational approaches for these calculations.
• To provide vibrationally averaged structural parameters for future studies on parity-violation effects.

Main Methods:

• High-level electronic structure calculations using the CCSD(T)/aug-cc-pVTZ method.
• Application of both variational and perturbational approaches to compute anharmonicity corrections.
• Comparison of computed spectra with available experimental data.

Main Results:

• Excellent agreement between computed and experimental vibrational spectra was achieved.
• Absolute mean deviations were approximately 4 cm⁻¹ for fundamental modes and 7 cm⁻¹ for first overtones.
• Vibrationally averaged structural parameters were successfully computed for both molecules.

Conclusions:

• The employed computational methods accurately reproduce experimental vibrational spectra for CHFClBr.
• The calculated data serve as a reliable basis for future investigations into parity-violation effects in chiral molecules.