Chemical reactivity from linear response eigenfunctions and eigenvalues

Area of Science:

• Quantum chemistry
• Computational chemistry

Background:

• The linear response function matrix is crucial for understanding molecular electronic properties.
• Diagonalization of this matrix yields eigenvectors that form a complete basis set.

Purpose of the Study:

• To introduce and define atom-condensed Electron Density Deformation Modes.
• To explore the utility of these modes in identifying molecular reactive regions and electron flow patterns.

Main Methods:

• Diagonalization of the atom-condensed linear response function matrix.
• Projection of density deformations onto the obtained eigenvectors.
• Derivation of relationships between electron density polarization energy and hardness variation.

Main Results:

• Eigenvectors are interpreted as Electron Density Deformation Modes.
• These modes describe electron density deformation in response to perturbations.
• A connection between polarization energy and hardness variation is established.

Conclusions:

• Electron Density Deformation Modes offer insights into molecular reactivity.
• These modes can predict preferred electron flow, aiding in the identification of reactive sites.
• The framework is applicable to practical studies of organic reactions.