Intermolecular potential energy surface and second virial coefficients for the water-CO2 dimer

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Molecular Interactions

Background:

• Understanding intermolecular forces is crucial for predicting gas behavior.
• Accurate potential energy surfaces are essential for molecular simulations and thermodynamic property calculations.

Purpose of the Study:

• To compute a five-dimensional potential energy surface for the water-CO2 system.
• To calculate second virial coefficients for water-CO2 interactions across various temperatures.
• To validate computational results against experimental data.

Main Methods:

• Utilized second-order Møller-Plesset perturbation theory and coupled-cluster theory.
• Employed basis set incompleteness correction for correlation energy.
• Calculated second virial coefficients and estimated their uncertainties.

Main Results:

• Identified the most stable structure with C(2v) symmetry, featuring water's oxygen near CO2's carbon.
• Computed second virial coefficients show excellent agreement with existing experimental values.
• The potential energy surface accurately describes the interaction energetics.

Conclusions:

• The calculated potential energy surface provides a reliable description of water-CO2 interactions.
• The study validates advanced computational methods for molecular systems.
• Accurate theoretical predictions of virial coefficients are achievable.