Vibrational Spectroscopy and Density Functional Theory in Chemical Systems

Vibrational spectroscopy, encompassing infrared and Raman methods, provides direct insight into molecular bond strengths, conformations and intermolecular interactions by measuring characteristic vibrational frequencies. Density functional theory (DFT) complements these techniques by predicting electronic structures and potential energy surfaces using electron density functionals. Recent advances in hybrid exchange–correlation functionals and dispersion corrections have improved the accuracy of computed vibrational spectra, while force-field scaling approaches enhance mode assignments. Solvent effects are routinely included via self-consistent reaction-field models, and transport phenomena at the molecular scale are explored through non-equilibrium Green’s function formalisms. The integration of experiment and theory now underpins applications across materials science, energy conversion, catalysis and pharmaceutical design, enabling rigorous interpretation of spectroscopic signatures and guiding the rational design of functional chemical systems.

Research from Nature Portfolio

Recent studies have employed DFT coupled with non-equilibrium Green’s function techniques to probe the spectroscopic and electronic transport properties of photoactive biomolecules. Detailed analyses of retinal isomers in rhodopsin reveal how infrared and Raman spectra correlate with conformational changes during photoisomerisation. By performing complete vibrational assignments using a scaled quantum mechanical force-field approach, researchers have linked specific normal modes to conductivity variations in molecular junctions. Systematic evaluation of electrode materials and binding sites demonstrated that nanoscale contacts can modulate the highest occupied–lowest unoccupied molecular orbital gap, providing a pathway to design optoelectronic switches with tailored spectral responses.

Vibrational Spectroscopy and Density Functional Theory in Chemical Systems publication trend

The graph below shows the total number of articles in vibrational spectroscopy and density functional theory in chemical systems across all publications each year (not limited to Nature Index journals).

Technical terms

Density Functional Theory (DFT): Quantum mechanical method that models electronic structure using functionals of the electron density.

Vibrational Spectroscopy: Analytical technique probing molecular vibrations by measuring absorption or scattering of light.

Infrared (IR) Spectroscopy: Vibrational spectroscopy method that detects absorption of infrared radiation by molecular bonds.

Raman Spectroscopy: Technique that analyses inelastically scattered light to identify vibrational modes.

Non-equilibrium Green’s Function (NEGF): Formalism to simulate electronic transport through molecular systems under bias.

Scaled Quantum Mechanical Force Field (SQMFF): Approach for adjusting computed force constants to improve agreement with experimental vibrational frequencies.

Self-Consistent Reaction Field (SCRF): Implicit solvent model representing solvation effects via a polarisable continuum around the solute.

HOMO–LUMO gap: Energy difference between the highest occupied and lowest unoccupied molecular orbitals, indicative of chemical reactivity.

References

1. Theoretical study on the structure, spectroscopic, and current–voltage behavior of 11-Cis and Trans retinal isomers in rhodopsin. Scientific Reports (2024).
2. Dehydrogenation versus deprotonation of disaccharide molecules in vacuum: a thorough theoretical investigation. Royal Society Open Science (2022).
3. Interaction between the L-Ascorbic Acid and the HO2 Hydroperoxyl Radical: An Ab Initio Study. Crystals (2023).
4. Mechanical-Quantum Calculations of Base Free, Cationic and Hydrochloride Forms of Semisynthetic Antibiotic Clindamycin. European Journal of Theoretical and Applied Sciences (2024).