Exploring the Infrared Spectrum through QTAIM Properties

The infrared intensities are a rich source of information about the electronic density and its changes when atoms move within a normal coordinate. Such information can be accessed by the charge-charge transfer-dipolar polarization (CCTDP) model.

In this presentation, we demonstrate how the CCTDP atomic contributions are calculated via the formalism of the Quantum Theory of Atoms in Molecules, highlighting the importance of taking atomic polarizations into account.

As the intensity, the force constants of normal mode can also be decomposed into atomic contributions employing the Interactive Quantum Atoms energy decomposition scheme, allowing the reconstruction of the infrared spectrum using only topological properties.