Vibrational Relaxation in Liquids

Oxtoby, David W.

doi:10.1146/annurev.pc.32.100181.000453

Cited by 490 publications

(468 citation statements)

References 0 publications

Supporting

Mentioning

455

Contrasting

Unclassified

Order By: Relevance

“…The 3ν 3 shift is somewhat more than the shift observed for the CO asymmetric stretch of W(CO) 6 in CO 2 , and the C-H stretch shift is somewhat less. No obvious manifestation of critical phenomena is observed in these data, but at 50°C, which is substantially above T c for CO 2 , it is not clear that any would be observed even if critical phenomena were important on a near critical isotherm. The spectral data for the asymmetric CO stretch of W(CO) 6 in CO 2 on the 50°C and 33°C (near critical) isotherms are so similar (as are the T 1 (F,T) data on the same isotherms) that they do not suggest any special attributes of critical phenomena are important.…”

Section: Discussionmentioning

confidence: 55%

“…All pump-probe measured lifetime decays of the CO asymmetric stretch of W(CO) 6 in SC solvents ethane, CO 2 and fluoroform, over a wide range of densities (>1 mol/L) and temperatures, are single exponentials. 7,8,36 A single exponential (aside from orientational relaxation in liquids) is observed even when very fast pulses are used in the experiments.…”

Section: Resultsmentioning

confidence: 99%

“…2 For a diatomic, ω is the oscillator frequency. However, for a polyatomic, an initially high-frequency mode can relax into lower frequency intramolecular modes, and ω is the fraction of the initially excited oscillator energy that is deposited into the solvent.…”

Section: Theory Of T 1 Density Dependencementioning

confidence: 99%

See 2 more Smart Citations

Vibrational Lifetimes and Spectral Shifts in Supercritical Fluids as a Function of Density: Experiments and Theory

et al. 2000

View full text Add to dashboard Cite

Vibrational lifetime and spectral shift data for the asymmetric CO stretching mode of W(CO) 6 in supercritical ethane, carbon dioxide, and fluoroform as a function of density at two temperatures are presented, and the lifetime (T 1 ) measurements are compared to theory. The data and theory are refinements of previous work. Measurements at zero density allow the contribution from solute-solvent interactions to be separated from strictly intramolecular contributions to T 1 . The results in the polyatomic SCFs are compared to data in Ar. The density functional/thermodynamic theory 1 has been extended to include contributions at large wavevector (k). Very good, quantitative agreement between theory and data taken in ethane and fluoroform is achieved, but the agreement for data taken in carbon dioxide, while reasonable, is not as good. The theory uses a variety of input information on the SCF properties obtained from the fluids' equations of state and other tabulated thermodynamic data. The solute-solvent spatial distribution is described in terms of hard spheres. The theory is able to reproduce the data without solute-solvent attractive interactions or clustering in the calculation of the spatial distribution.

show abstract

Section: Discussionmentioning

confidence: 55%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Vibrational Lifetimes and Spectral Shifts in Supercritical Fluids as a Function of Density: Experiments and Theory

et al. 2000

View full text Add to dashboard Cite

show abstract

“…1 One possible application of vibrationally adiabatic QC simulations is the study of vibrational dephasing in condensed phases. [2][3][4][5][6][7][8][9][10] Oxtoby and co-workers have obtained the dephasing times of diatomic molecules in condensed phase environments by using perturbation theory to calculate the time-dependent fluctuations in the vibrational energy levels. 9,10 A completely classical simulation was used with rigid molecules so that there was no influence of the quantum-mechanical system on the classical motion.…”

Section: Introductionmentioning

confidence: 99%

“…This approach has been widely and successfully used for weakly coupled solute-solvent systems. [9][10][11][12][13] A vibrationally adiabatic QC simulation directly provides the fluctuating frequencies of a quantum-mechanical solute from dynamics that include response from the quantum mode͑s͒ onto the classical coordinates. Further, an explicit calculation of the vibrational energy levels is accurate even for strong solute-solvent coupling, unlike perturbation theory approaches.…”

Section: Introductionmentioning

confidence: 99%

A general method for implementing vibrationally adiabatic mixed quantum-classical simulations

Thompson

2003

The Journal of Chemical Physics

View full text Add to dashboard Cite

An approach for carrying out vibrationally adiabatic mixed quantum-classical molecular dynamics simulations is presented. An appropriate integration scheme is described for the vibrationally adiabatic equations of motion of a diatomic solute in a monatomic solvent and an approach for calculating the adiabatic energy levels is presented. Specifically, an iterative Lanczos algorithm with full reorthogonalization is used to solve for the lowest few vibrational eigenvalues and eigenfunctions. The eigenfunctions at one time step in a mixed quantum-classical trajectory are used to initiate the Lanczos calculation at the next time step. The basis set size is reduced by using a potential-optimized discrete variable representation. As a demonstration the problem of a homonuclear diatomic molecule in a rare gas fluid (N 2 in Ar͒ has been treated. The approach is shown to be efficient and accurate. An important advantage of this approach is that it can be straightforwardly applied to polyatomic solutes that have multiple vibrational degrees-of-freedom that must be quantized.

show abstract

Ultrafast infrared-Raman studies of vibrational energy redistribution in polyatomic liquids

Deàk

Iwaki

Rhea

et al. 2000

J. Raman Spectrosc.

View full text Add to dashboard Cite

Vibrational energy relaxation and vibrational cooling of polyatomic liquids were studied with the ultrafast infrared-Raman (IR-Raman) technique. In the IR-Raman technique, a type of two-dimensional vibrational spectroscopy, a vibrational transition is pumped with a mid-infrared pulse and the instantaneous populations of all Raman-active transitions are simultaneously probed via incoherent anti-Stokes Raman scattering of a time-delayed visible pulse. The theoretical framework for these measurements, including force-force correlation function methods and perturbative techniques, is reviewed. Experimental aspects of the IR-Raman technique are discussed, including laser instrumentation, experimental set-up, the nature of the pumping and probing processes, detection sensitivity and optical background, and the interpretation of results including spectroscopic artifacts. Then examples are provided from recent research by our group, focusing on timely problems such as the pseudo-vibrational cascade, the dynamics of doorway vibrations, dynamics of overtones with Fermi resonance, multiple vibrational excitations via combination band pumping and spectral evolution in associated liquids.

show abstract

Vibrational Relaxation in Liquids

Cited by 490 publications

References 0 publications

Vibrational Lifetimes and Spectral Shifts in Supercritical Fluids as a Function of Density: Experiments and Theory

Vibrational Lifetimes and Spectral Shifts in Supercritical Fluids as a Function of Density: Experiments and Theory

A general method for implementing vibrationally adiabatic mixed quantum-classical simulations

Ultrafast infrared-Raman studies of vibrational energy redistribution in polyatomic liquids

Contact Info

Product

Resources

About