Computing Bulk Phase Raman Optical Activity Spectra from ab initio Molecular Dynamics Simulations.

Area of Science:

• Computational Chemistry
• Spectroscopy
• Quantum Mechanics

Background:

• Raman optical activity (ROA) spectroscopy provides valuable information on molecular structure and chirality.
• Calculating ROA spectra for liquid systems, especially in bulk phases, presents significant computational challenges.
• Existing methods often require computationally expensive perturbation theory or are limited to smaller systems.

Purpose of the Study:

• To introduce a novel, efficient methodology for computing ROA spectra of liquid systems.
• To enable the calculation of ROA spectra for large, complex periodic bulk phase systems.
• To provide an alternative to time-consuming perturbation theory methods for ROA calculations.

Main Methods:

• The methodology utilizes ab initio molecular dynamics (AIMD) simulations as input.
• It incorporates recent advancements in obtaining magnetic dipole moments from AIMD.
• Radical Voronoi tessellation is employed to integrate molecular properties for optical activity tensor calculations.

Main Results:

• The developed method successfully computes ROA spectra for periodic bulk phase systems.
• The approach relies solely on total electron density from AIMD, avoiding perturbation theory.
• The computed ROA spectrum for liquid (R)-propylene oxide closely matches experimental data.

Conclusions:

• This novel AIMD-based approach offers an efficient and accurate way to compute ROA spectra for liquid systems.
• It is the first method to compute ROA spectra for periodic bulk phase systems.
• The technique is versatile and can be combined with various electronic structure methods.