Fluorescence and phosphorescence are photon emission processes that occur during molecular relaxation from electronic excited states. These photonic processes involve transitions between electronic and vibrational states of polyatomic fluorescent molecules (fluorophores). The Jablonski diagram (Figure 1) offers a convenient representation of the excited state structure and the relevant transiti...

Heavy Rydberg states are analogs of electronic Rydberg states, but with the electron replaced by a much heavier ion. We calculate ab initio the extremely long-range vibrational H(+)H(-) heavy Rydberg states in H(2), and compare these to recent experiments. The calculated resonance positions and widths agree well with experiment, but we predict additional sharp interloper resonances correspondin...

First-principle calculations were carried out to investigate the adsorption of CO over Cun nanoclusters. The structural, spectroscopic and electronic properties like optimized geometries, HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, binding energy, adsorption energy, vibrational frequency and density of states (DOSs) of the p...

Quantum dynamical simulations of vibrational spectroscopy have been carried out for glycine dipeptide (CH(3)-CO-NH-CH(2)-CO-NH-CH(3)). Conformational structure and dynamics are modeled in terms of the two Ramachandran dihedral angles of the molecular backbone. Potential energy surfaces and harmonic frequencies are obtained from electronic structure calculations at the density functional theory ...

We introduce a point of view for treating the dynamical tunneling splitting of symmetric local mode vibrational states in ABA molecules (A = H typically) which is the one we have employed in treating the vibrational spectroscopy of CH overtones in molecules such as (CXs),YCCH. Namely, the vibrational coupling corresponding to the dynamical tunneling in semiclassical mechanics via many intermedi...

In atomic nuclei, ordered and chaotic states generally coexist. In this paper the transition from ordered to chaotic states will be discussed in the framework of roto–vibrational and shell models. In particular for 160Gd, in the roto–vibrational model, the Poincarè sections clearly show the transition from order to chaos for different values of rotational frequency. Furthermore, the spectral st...

The ground and excited vibrational states for the three hydrogen isotopes on the Pd(111) surface have been calculated. Notable features of these states are the high degree of anharmonicity, which is most prominently seen in the weak isotopic dependence of the parallel vibrational transition, and the narrow bandwidths of these states, which imply that atomic hydrogen is localized on a particular...

Ab initio electronic structure calculations on several low-lying valence states of B, have been carried out using correlation-consistent polarized valence double-zeta basis sets and completeactive-space self-consistent field treatments of electron correlation. Stable triangular structures, linear structures, and Jahn-Teller unstable structures are all observed. Equilibrium geometries, energies,...

First-principle calculations were carried out to investigate the adsorption of CO over Cun nanoclusters. The structural, spectroscopic and electronic properties like optimized geometries, HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy levels, binding energy, adsorption energy, vibrational frequency and density of states (DOSs) of the p...

Using photoelectron spectroscopy in combination with synchrotron radiation, we have observed previously inaccessible vibrational excitation of HI+ X 2113,z, X 2111,2 final ionic states. The vibrational enhancement is shown to be caused by strongly predissociating autoionization resonances converging to HI+ A ?Z+. Molecular vibrational constants are extracted from the photoelectron spectra obtai...