Potential energy surface and MULTIMODE vibrational analysis of C2H3+

Area of Science:

• Computational Chemistry
• Theoretical Chemistry
• Chemical Physics

Background:

• Accurate potential energy surfaces (PES) are fundamental for understanding molecular dynamics and reaction mechanisms.
• The C(2)H(3)(+) ion is an important intermediate in various chemical processes, necessitating a detailed theoretical description.

Purpose of the Study:

• To develop a high-quality, full-dimensional, ab initio-based semiglobal potential energy surface for the C(2)H(3)(+) cation.
• To provide a reliable computational tool for future investigations of the dynamics and spectroscopy of C(2)H(3)(+).

Main Methods:

• Ab initio electronic energies were computed using the spin-restricted, coupled cluster method with singles and doubles, including triples corrections (RCCSD(T)).
• A correlation-consistent polarized valence triple-zeta basis set augmented with diffuse functions (aug-cc-pVTZ) was employed.
• The PES was constructed using a many-body (cluster) expansion with symmetry-adapted functions.

Main Results:

• A validated semiglobal potential energy surface for C(2)H(3)(+) was successfully generated.
• The fitted PES accurately reproduced normal mode frequencies at the global and secondary minima compared to direct ab initio calculations.
• The developed PES was utilized in vibrational analysis using the MULTIMODE code.

Conclusions:

• The generated potential energy surface represents a significant advancement for theoretical studies of C(2)H(3)(+).
• This work provides a robust foundation for exploring the vibrational dynamics and reaction pathways involving the C(2)H(3)(+) ion.