The interaction between localized and extended vibrational modes in solids is of central importance in understanding how local vibrational modes (LVMs) decay into phonons. In this study, we have investigated interstitial oxygen (Oi) in silicon as a model ‘laboratory’ for such local-extended mode interactions. Using hydrostatic pressure and infrared spectroscopy, we brought the stretch mode of O...

The vibrational nonlinear dynamics of HOBr in the bending and O-Br stretching coordinates with anharmonicity and Fermi 2:1 coupling are studied with dynamical potentials in this article. The result shows that the H-O stretching vibration mode has significantly different effects on the coupling between the O-Br stretching mode and the H-O-Br bending mode under different Polyad numbers. The dynam...

Ultrafast UV-vibrational spectroscopy was used to investigate how vibrational excitation of the bridge changes photoinduced electron transfer between donor (dimethylaniline) and acceptor (anthracene) moieties bridged by a guanosine-cytidine base pair (GC). The charge-separated (CS) state yield is found to be lowered by high-frequency bridge mode excitation. The effect is linked to a dynamic mod...

We have recorded several rovibronic bands of CH3OO and CD3OO in their A<--X transitions in the range of 1.18-1.40 microm with the cavity ringdown technique. While the electronic origins for these species have been reported previously, many newly observed rovibronic bands are described here. The experimental vibrational frequencies (given as nu in the unit cm(-1) in this paper) for the COO bendi...

Vibrational properties of graphene nanoribbons are examined with density functional based tight-binding method and non-resonant bond polarization theory. We show that the recently discovered reconstructed zigzag edge can be identified from the emergence of high-energy vibrational mode due to strong triple bonds at the edges. This mode is visible also in the Raman spectrum. Total vibrational den...

Ultrafast infrared spectroscopy can reveal the dynamics of vibrational excitations in matter. In its conventional far-field implementation, however, it provides only limited insight into nanoscale sample volumes due to insufficient spatial resolution and sensitivity. Here, we combine scattering-scanning near-field optical microscopy (s-SNOM) with femtosecond infrared vibrational spectroscopy to...

The calculation of thermochemical data requires accurate molecular energies and heat capacities. Traditional methods rely upon the standard harmonic normal-mode analysis to calculate the vibrational and rotational contributions. We utilize path-integral Monte Carlo for going beyond the harmonic analysis and to calculate the vibrational and rotational contributions to ab initio energies. This is...

Multiple vibrational mode coupling that induces the missing mode effect and Duschinsky rotation on the potential energy surface of the S(1) state in the Cy3 molecule was clarified by real-time ultrafast spectroscopy with a few-cycle laser pulse. The contributions of homogeneous and inhomogeneous dephasing to the total dephasing time were found to be 55% and 45%, respectively.