Vibrational spectroscopy: can density functional theory cope with highly electronegative atoms?

Area of Science:

• Computational chemistry
• Molecular spectroscopy
• Quantum chemistry

Background:

• Vibrational properties are crucial for understanding molecular structure and reactivity.
• Molecules composed of highly electronegative atoms (e.g., F, O, N) present unique computational challenges.
• Density functional theory (DFT) is a widely used method for electronic structure calculations.

Purpose of the Study:

• To investigate the vibrational properties of molecules containing only highly electronegative atoms.
• To evaluate the performance of various exchange-correlation functionals in DFT for these specific molecular systems.
• To identify reliable computational methods for simulating infrared spectra of such compounds.

Main Methods:

• Utilizing density functional theory (DFT) computational methods.
• Testing a range of exchange and correlation functional combinations.
• Calculating and analyzing vibrational frequencies and infrared spectra.

Main Results:

• Demonstrated that specific DFT functionals can accurately predict vibrational properties.
• Successfully simulated infrared spectra for molecules composed solely of fluorine, oxygen, and nitrogen.
• Identified key functional combinations that perform well for these electron-rich systems.

Conclusions:

• Certain density functional approximations are suitable for studying the vibrational spectra of highly electronegative molecules.
• The findings provide a validated computational approach for future research on similar chemical systems.
• This work contributes to the accurate prediction of molecular vibrational behavior in challenging chemical environments.