Isotopic Effects on the Structure and Spectroscopy of Thioformaldehyde, Dihydrogen and Water

This research presents a comprehensive computational study of deuterated molecular species, namely SCH۲, H۲, and H۲O, focusing on the impact of deuteration on their spectroscopic properties. Utilizing advanced quantum chemical methods, including MP۲/cc-pVDZ, MP۲/۶-۳۱۱*, G۴, W۲U, and CCSD/cc-pVDZ, the molecular geometries of the deuterated species were optimized to investigate their dipole moments, vibrational frequencies, and rotational constants. The vibrational frequencies provided insights into molecular vibrations, while the rotational constants described rotational motion. In addition, bond lengths and bond angles were computed to understand the molecular structure and bonding patterns. Subsequently, dipole moments were analyzed to assess polarity and charge distribution. The results revealed significant alterations in the spectroscopic properties due to deuteration, leaving the structural properties unaffected.