Accurate Induction Energies for Small Organic Molecules:  1. Theory

Area of Science:

• Computational Chemistry
• Molecular Modeling
• Quantum Chemistry

Background:

• Induction energy significantly influences organic molecule cluster structure and properties.
• Accurate inclusion of induction energy in calculations has been a recent focus, particularly for organic crystal structure prediction.
• Existing methods may not fully capture the complexities of induction energy for larger molecular systems.

Purpose of the Study:

• To develop and present ab initio methods for accurately including induction energy in molecular calculations.
• To provide techniques suitable for molecules containing up to approximately 30 atoms.
• To investigate the impact of various factors on induction energy calculations.

Main Methods:

• Utilizing Symmetry-Adapted Perturbation Theory using Density Functional Theory [SAPT(DFT)].
• Employing distributed polarizabilities computed via a density-fitting algorithm with constrained refinement.
• Developing induction models of varying complexity to analyze overlap and numerical issues.

Main Results:

• The developed methods allow for accurate computation of induction energy for moderately sized organic molecules.
• Analysis of basis set effects on both exact and asymptotic induction energies was performed.
• The influence of higher-order induction energies and many-body effects was explored.

Conclusions:

• The presented ab initio methods offer a robust approach for incorporating induction energy in molecular studies.
• These techniques facilitate a deeper understanding of intermolecular interactions and their impact on molecular properties.
• The study provides valuable tools for advancing organic crystal structure prediction and related computational chemistry fields.