Rovibrational structure of the Xe-CO complex based on a new three-dimensional ab initio potential

Area of Science:

• Computational Chemistry
• Molecular Interactions
• Spectroscopy

Background:

• Understanding intermolecular forces is crucial for predicting molecular behavior.
• Accurate potential energy surfaces (PES) are essential for simulating molecular dynamics and spectroscopy.
• Previous studies lacked a comprehensive 3D PES for the Xe-CO system.

Purpose of the Study:

• To compute the first three-dimensional interaction potential energy surface (3D PES) for the Xe-CO complex.
• To accurately determine rovibrational energy levels and transition frequencies.
• To validate the computational model against experimental spectroscopic data.

Main Methods:

• Employed coupled cluster theory with noniterative treatment of triple excitations (aug-cc-pVQZ and aug-cc-pVQZ-PP basis sets).
• Developed an analytic two-dimensional potential model fitted to calculated single-point energies.
• Constructed the 3D PES by interpolating model potentials and performed dynamical calculations using vibrationally averaged potentials.

Main Results:

• Successfully generated the first 3D interaction potential energy surface for the Xe-CO complex.
• Calculated rovibrational energy levels and transition frequencies showed excellent agreement with experimental data.
• Precisely reproduced 508 infrared (IR) transitions with a root-mean-square error of 0.105 cm⁻¹.

Conclusions:

• The developed 3D PES provides a highly accurate representation of the Xe-CO interaction.
• The computational approach validates the ability to predict spectroscopic properties of weakly bound complexes.
• This work serves as a benchmark for future studies on noble gas-molecule interactions.