Cluster integrals and virial coefficients for realistic molecular models.

Area of Science:

• Computational Chemistry
• Chemical Physics
• Thermodynamics

Background:

• Thermodynamic virial coefficients are crucial for understanding molecular interactions.
• Calculating these coefficients often involves complex cluster integrals.
• Existing methods can be computationally intensive or limited in scope.

Purpose of the Study:

• To develop a general and efficient procedure for calculating cluster integrals.
• To link thermodynamic virial coefficients directly to molecular interactions.
• To enable the evaluation of derivatives of virial coefficients.

Main Methods:

• A concise and general computational procedure for cluster integrals.
• Incorporation of nonpairwise intermolecular potentials from quantum chemistry.
• Extension for efficient evaluation of temperature and other derivatives.

Main Results:

• Demonstration of the method using a polarizable water model.
• Successful calculation of cluster integrals relating molecular interactions to virial coefficients.
• Efficient computation of virial coefficient derivatives.

Conclusions:

• Cluster-integral methods are powerful tools for first-principles molecular modeling.
• The presented procedure enhances the utility and accessibility of these methods.
• This approach facilitates the development and application of advanced molecular models.