High-Level Ab Initio Calculations of Intermolecular Interactions: Heavy Main-Group Element π-Interactions

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Chemical Physics

Background:

• Understanding intermolecular interactions is crucial in chemistry and materials science.
• Heavy main-group elements exhibit unique electronic properties influencing their interactions.
• Accurate theoretical methods are needed to describe weak interactions involving these elements.

Purpose of the Study:

• To investigate intermolecular interactions between heavy main-group element compounds (MR3, M=As, Sb, Bi; R=CH3, OCH3, Cl) and π systems.
• To benchmark various computational methods for describing weak interactions.
• To elucidate the nature of dispersion and donor-acceptor interactions in these systems.

Main Methods:

• High-level ab initio calculations.
• Benchmarking of Density Functional Theory with dispersion correction (DFT-D), DFT-SAPT, Møller-Plesset perturbation theory (MP2), and localized pair-natural orbital coupled cluster with singles, doubles, and perturbative triples (DLPNO-CCSD(T)).
• Local energy decomposition (LED) and electron density analysis.

Main Results:

• Detailed insights into dispersion and donor-acceptor interactions were obtained.
• Systematic periodic trends in intermolecular interactions were identified.
• The study provides a benchmark for dispersion interactions in heavy main-group compounds.

Conclusions:

• Advanced computational methods accurately describe intermolecular interactions in heavy main-group compounds.
• Understanding these interactions is vital for predicting properties and designing new materials.
• The findings offer valuable reference data for future theoretical and experimental studies.