SAPT codes for calculations of intermolecular interaction energies

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Theoretical Chemistry

Background:

• Accurate calculation of intermolecular interaction energies is crucial for understanding molecular systems.
• Symmetry-adapted perturbation theory (SAPT) is a leading method for computing noncovalent interactions.

Purpose of the Study:

• To present the SAPT2020 code, a comprehensive suite of SAPT variants.
• To facilitate the development of potential energy surfaces (force fields) for molecular systems.

Main Methods:

• Implementation of various SAPT formulations, including two-body and three-body SAPT.
• Integration of perturbative, coupled cluster, and density functional theory approaches.
• Development of automated procedures for generating potential energy surfaces.

Main Results:

• SAPT2020 encompasses a wide range of SAPT variants for diverse monomer types (closed- and open-shell).
• Automated surface generation is demonstrated for dimers up to ~100 atoms using rigid monomer approximation.
• Capability to generate surfaces including monomer internal degrees of freedom is included.

Conclusions:

• SAPT2020 provides a versatile and powerful tool for accurate calculation of intermolecular interactions.
• The code enables efficient generation of high-quality potential energy surfaces for diverse chemical systems.