IR spectra, (resonance) Raman, VCD

In ADF infrared and Raman spectroscopy can be studied for molecular vibrations. In the Born-Oppenheimer and harmonic approximations the vibrational frequencies are determined by the normal modes corresponding to the molecular electronic ground state potential energy surface.

In resonance Raman spectroscopy the molecule is excited to near one of its electronic excited states, to improve the sensitivity compared to traditional Raman spectroscopy.

Vibrational circular dichroism (VCD) is the differential absorption of left and right circularly polarized infrared light by vibrating molecules.

Franck-Condon factors are the squares of the overlap integrals of vibrational wave functions. Given a transition between two electronic, spin or charge states, the Franck-Condon factors represent the probabilities for accompanying vibrational transitions.

IR frequencies and intensities can be calculated in ADF with analytical and numerical second derivatives implementations. Raman scattering intensities and depolarization ratios for all molecular vibrations or for a range of frequencies can be calculated. Starting from ADF2006 it is possible to calculate relative intensities of resonance Raman. Starting from ADF2007 it is possible to calculate the VCD spectrum.

• Scalar relativistic effects (ZORA) can be included
• Code is parallelized

Links

ADF User Documentation: IR Frequencies, Raman, resonance Raman, VCD, Franck-Condon factors
ADF-GUI: spectroscopic properties
Examples: IR Frequencies, (resonance) Raman, VCD, Franck-Condon factors
References: IR frequencies, Raman, VCD