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The importance of the substrate field inhomogeneities in the optical response of an adsorbate experiencing a resonant Raman scattering process is studied. The analysis reveals that the number of intermediate vibrational levels becomes very large for a strong substrate field.

The structure, stability and vibrational properties of isolated V2O5 clusters on the Al2O3(0001) surface are investigated by density functional theory (DFT) and statistical thermodynamics. It is shown that small (V2O5) vanadium clusters on alpha-Al2O3(0001) are more difficult to reduce than the (001) V2O5 crystal surface, but significantly easier than thin films.

The authors investigate how efficient the mode-tracking protocol can be applied to determine vibrational parameters for a particular type of normal modes of dinuclear polyynediyl rhenium complexes. The frequencies of vibrations of the carbon chain in certain complexes are studied as a function of the chain length 2n, leading to molecules with upto 144 atoms, for which harmonic wavenumbers are determined.

A study was conducted to analyze the vibrational dynamics of alpha,alpha-trehalose-water solutions. O-H stretching region analysis was carried out using a decomposition of the isotropic spectra into an open and closed contribution along with a spectral stripping procedure. Experimental results indicated that trehalose hinders the crystallization process and minimizes the amount of freezable water.

A study was conducted to analyze potential energy surfaces involving the ring-puckering vibration of 2,5-dihydrothiophene. Far-infrared spectra were determined using a Digilab FTS-20E spectrometer supporting a helium-cooled bolometer detector. The samples were stored in a Wilkes variable long-path cell with variable path lengths of 4 to 20 m. In addition, the interaction between the puckering and the in-plane ring angle bending was examined.

A study was conducted to examine Fe(IV)=O model complexes using energy second derivatives determined with nonlocal density functional theory using full vibrational analyses. Theoretical methods were utilized in the study. These methods supported full geometry optimizations, spin-unrestricted computations and analytical frequencies. Results suggested that the 356 cm(super -1) band of CcO is a ferryl tilting mode.

This study examined the dynamics involved when an electronically nonadiabatic process couples to two underdamped vibrational degrees of freedom. Using numerical solutions of the multilevel Redfield equations, the analysis examined how the electronic population dynamics and product vibrational dynamics are affected by the degree to which the Franck-Condon active modes extend onto the reactive motion. Findings revealed that the competition between coherent vibrational motion and energy and phase relaxation generates electronic and nuclear dynamics that are sensitive to the location of and force acting on the initially prepared wave packet.

A study was conducted to analyze the two lowest-lying electronic states of the VF3 molecule. The coupled-cluster singles and doubles level methods were utilized to carry out the analysis. The Jahn-Teller effect in one of the states was also examined. Assumptions regarding the stretching area of the VF3 vibrational spectrum were then discussed. Experimental results indicated that the frequency of VF3 in the 3E'' state may be around 670 cm(super -1).

The concurrence between vibrational sudden approximation (VSA) and exact probabilities for a number of new collision systems was investigated. This analysis was useful in deriving lower and less restrictive values for validity criteria, which then helped in ascertaining which of the collinear atom-triatom or diatom-diatom collision systems is more relevant to VSA. The specific lower bound for the atom-triatom was 14 and that for the diatom-diatom validity criteria was six.

The frequency-resolved sub-picosecond infrared spectroscopy is employed to study the ultrafast dynamics of the carbonyl CO stretching vibration in acetic acid in aqueous solution. The two acetic acid components are shown to exhibit almost similar bond shape and time constants.

The Lanczos eigenvalue analysis method is employed for carrying out the quantum calculations of the different ro-vibrational states. The approach is shown to be applicable and highly accurate for the DOCI system.

The electronic structure calculations are employed to predict and measure the vibrational ion frequencies of the uranyl, [UO.sub.2.sup.2+] complex at the coupled cluster (CCSD(T)) level. The impact of anharmonicity and spin-orbit corrections on the harmonic frequencies is also discussed.

The article discusses the impact of the low-energy electrons on the resonant vibrational excitation and de-excitation of [N.sub.2](v). The electron energy distribution functions and the rate coefficients of these molecules are also determined.

The variational transition state analysis approach is employed to study the parameters involved in the barrierless phenyl + [O.sub.2] and phenoxy + O reactions. Both the addition reactions are shown to exhibit loose transition state structures.

The development of a new model for octupolar dyes that accounts for the coupling of electrons to molecular vibrations and for solvation effects is described. The spectroscopic behavior of dyes in solution is studied.

The vibrational energy relaxation (VER) of the hydrogen stretch in a linear hydrogen-bonded complex dissolved in a polar solvent is analyzed by using the mixed quantum-classical Liouville method. The results have helped in understanding the problem of VER in strongly coupled condensed phase systems that are outside the range of validity of the Landau-Teller formula.

A theoretical study of molecular, electronic, and vibrational properties of the first excited state of the phenoxyl radical, A [super 2][B.sub.2], is presented. The results indicate that both the ground-state and the first excited-state wave functions are strongly dominated by single electronic configurations.

The quasi-classical trajectory (QCT) calculation results are described on a model potential energy surface (PES) for the C[H.sub.3][O.sub.2] + NO reaction. The findings provide insight into significant role of non-Rice-Ramsperger-Kassel-Marcus (RRKM) rate of reaction and vibrational anharmonicity for organic nitrate yields.

The low-frequency vibrational coherence in the bacteriochlorophyll (BChl)-containing subunit proteins B777 and B820 from the LH1 light-harvesting complex isolated from Rhodospirillum rubrum G9 has displayed rapidly dmped modulation components arising from intermolecular nonbonding interactions. The results have shown that the dominant contributions to the optical and Marcus charge-transfer reorganization energies of BChl in proteins have come from van der Waals interactions rather than from intrachromophore modes.

The vibrational motions of the model peptide unit are analyzed by using formamide as dynamical models. The one-dimensional problem based on the separation of the amide out-of-plane motion from the rest of the peptide unit motions has provided the correct description of the effective eground-stateE molecular geometry for all studied systems.

Rotationally resolved fluorescence excitation spectra of the [0.sub.0.sup.0] bands of the [S.sub.1]

The intramolecular vibrational redistribution (IVR)-assisted ionization-gain stimulated Raman spectroscopy (IGSRS) and the jet-cooled fluorene are described. The fluorene spectra has shown extensive vibrational coupling interactions involving both the aliphatic and aromatic CH-stretching first excited states with nearby background states.

The density functional theory (DFT) calculations of vibrational frequencies are used for determining the isotope fractionation factors versus Mo[O.sub.4.sup.2-]. The results have shown that isotope equilibration of Mo[O.sub.4.sup.2-] with Mo[O.sub.3][([H.sub.2]O).sub.3] is responsible for the isotope fractionation of Mo between oxic sediments and seawater.

The infrared spectra of HCl, [(HCl).sub.2], and [H.sub.2]O-HCl in liquid helium nanodroplets are analyzed. The HCl-[H.sub.2]O complex has very large red shift and broadening of the transition, which is due to the interaction of the helium environment with low-lying vibrations of the complex.

Various scale factors that help in obtaining the harmonic vibrational frequencies are derived and explained. The results confirm the existence of an almost linear relationship between the magnitude of scale factor and the proportion of exact change.

A model Hamiltonian consisting of a harmonic oscillator and parturition is employed to study the vibronic transitions between two symmetric-double wall potentials. The inversion modes of ammonia and nitrogen-vacancy defect centers in diamond are also examined.

Infrared spectra of chlorinated ethylene cations such as [C.sub.2][Cl.sub.4.sup.+], [C.sub.2]H[Cl.sub.3.sup.+], 1,1-[C.sub.2][H.sub.2][Cl.sub.2.sup.+], and trans-[C.sub.2][H.sub.2][Cl.sub.2.sup.+] isolated in solid argon, is presented. The results show that the cations can be regarded as 'isolated' with the vibrational frequencies which are slightly shifted compared to the available gas-phase values.

The frequencies and intensities of the hydrogen-bonded OH-stretching transitions in the water dimmer complex are calculated along with the investigation of the effects of counterpoise correcting the potential energy surface and dipole moment function. It is found that the effect of using a numeric potential is significant for higher overtones.

An application of the direct potential fit (DPF) procedure to the large spectroscopic database containing all available HF/DF [X.sup.1.SIGMA.sup.+] pure-rotational and vibration-rotational transitions, as well as the rotationally hot B [sup.1.SIGMA.sup.+]--> [X.sup.1.][SIGMA.sup.+] emission band systems of both isotopologues is presented.

Mechanistic details of a prototype reaction H + HF(v) is analyzed on the basis of quasiclassical trajectory calculations. It is observed that the total energy available for the partners is below the exchange barrier, because at low translational energies the product F atom of a successful abstraction step re-abstracts the H atom from the intermediate product [H.sub.2] molecule that is originally the attacker.

Influence of fluorine substitutions on the stability of benzene is examined by using the Hartree-Fock (HF) and MP2 models. The homodesmotic reactions based on the open-chain zigzag polyenes are unsatisfactory and the result implies that both sigma- and pi-frameworks contribute to the aromatic stabilization of benzene in which the latter is more important.

A hybrid quatic force field with quartic force constants calculated at the CCSD(T)/cc-pVTZ level and cubic and quartic terms determined by a B3LTP/cc-pVTZ treatment is proposed to compute the vibrational energy levels of acetonitrile from a variational method. Fundamentals and overtones calculated in the range of 300-3200cm(super -1) are in fair agreement with the observed data, with an absolute mean deviation of less than 0.8%.

An accurate characterization of the three-dimensional potential energy surface and vibrational-rotational energy levels of calcium dihydride is presented. The molecular parameters are determined by the ab initio approach using extensively correlated wave functions calculated with large correlation-consistent spdfgh basis sets and taking into account the 'outer-core' correlation effects of the calcium atom.

The rapid estimation of basis set error and correlation energy from partial charges method is improved to make superfluous the explicit zero-point energy and thermal correction calculations. The new method is faster than the previous rapid estimation of basis set error and correlation energy from partial charges method, without losing the precision.

Making automotive vehicles sound prool, without increasing the weight of the vehicle, is a challenge for the automotive sector. Users of automotive vehicles might encounter two types of sound--airborne-and structure-borne. [...]