Ab Initio Studies on Spectroscopic Constants for the HAsO Molecule

Area of Science:

• Computational Chemistry
• Molecular Spectroscopy

Background:

• The HAsO molecule's electronic ground state (X̃1A') properties require accurate theoretical investigation.
• Spectroscopic constants are crucial for understanding molecular behavior and interactions.

Purpose of the Study:

• To compute anharmonic force fields and spectroscopic constants for the HAsO molecule.
• To evaluate the accuracy of different computational methods and basis sets against experimental data.
• To provide reliable predictions for molecular properties.

Main Methods:

• Utilized MP2, B3LYP, B3P86, and B3PW91 computational methods.
• Employed cc-pVQZ and cc-pV5Z basis sets for calculations.
• Compared calculated geometries, rotational constants, vibrational frequencies, and anharmonic constants with experimental values.

Main Results:

• The B3LYP/cc-pV5Z theoretical level demonstrated the best agreement with experimental data.
• Calculated molecular geometries, rotational constants, and vibrational frequencies align well with experimental findings.
• Predicted cubic and quartic force fields, vibration-rotation interaction constants, centrifugal distortion constants, and Coriolis coupling constants are deemed reliable.

Conclusions:

• The B3LYP/cc-pV5Z method provides highly accurate spectroscopic constants for the HAsO molecule.
• The calculated anharmonic force fields and spectroscopic constants are reliable for future research.
• This study validates computational approaches for predicting molecular properties of similar species.