Estimation of Anharmonic Potential Constants. II. Bent XY2 Molecules

Kuchitsu, K.; Morino, Yonezo

doi:10.1246/bcsj.38.814

Cited by 336 publications

(89 citation statements)

References 24 publications

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“…It is interesting to note that also in ozone the stretching constants frr, frrr and frrTr dominate the whole rest of comparable interaction constants as was already found for many other triatomics studied so far, compare for instance 7 ' 16 ' 17 and also the recent review by Mills 20 .…”

Section: Calculation Of Force Constantssupporting

confidence: 56%

Anharmonic Force Field and Isotopic Relations of Ozone

Hennig¹,

Strey²

1976

Zeitschrift Für Naturforschung A

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The anharmonic force constants of ozone up to fourth order have been determined from recently published spectroscopic data of 16 03 and 18 Os . For the first time all experimental data presently available have been used in a least squares fit. Compared with recent work, the correct formula for the Darling-Dennison resonance parameter y has been used now. The nonuniqueness of the solution is discussed. In addition, isotopic rules for various spectroscopic parameters are derived.

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Section: Calculation Of Force Constantssupporting

confidence: 56%

Anharmonic Force Field and Isotopic Relations of Ozone

Hennig¹,

Strey²

1976

Zeitschrift Für Naturforschung A

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“…15) are similar to those with it, but Kc is only 0. 30. In addition, there are "polarization cage" effects 1 1-13 as seen for the low 5 kcal/mol barrier dynamics (see above), and the frozen solvent picture no longer applies.…”

Section: Collapsed Charge Modelmentioning

confidence: 99%

Molecular dynamics of a model S N1 reaction in water

Keirstead

Wilson

Hynes

1991

The Journal of Chemical Physics

112

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Results are presented from a computer simulation of the dynamics of a model SN1 reaction in water, very loosely based on the reaction t-BuCl→t-Bu++Cl−. Two diabatic electronic states are considered, covalent and ionic, which cross in the presence of the polar solvent. The curve crossing is treated in the electronically adiabatic limit, which gives rise to coupled reagent and solvent dynamics involving a mixed covalent/ionic adiabatic potential surface. The reaction dynamics are analyzed in terms of a simple solute reaction coordinate defined to be the t-Bu to Cl separation distance. By employing constraint dynamics techniques, the potential of mean force is determined as a function of this reaction coordinate. The time evolution of the reaction is followed in terms of the full molecular dynamics of all reagent and solvent atoms. Beginning with the largely covalently bound reactant t-BuCl, the following was observed: (i) how energy flows out of the water solvent bath into a solvent–reactant fluctuation driving the system to the top of the barrier, (ii) how barrier recrossings lower the reaction rate below the transition state theory prediction, and (iii) how the products slide down the barrier toward separated t-Bu+ and Cl−, dissipating their excess energy back into the solvent. The calculated transmission coefficient measuring the departure of the rate constant from its transition state theory value is 0.53±0.04. This is found to agree with the Grote–Hynes theory prediction, and also with its nonadiabatic solvation, frozen solvent limit, to within the estimated error bars. By contrast, Kramers’ theory incorrectly predicts a much smaller value.

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“…The relationship between the anharmonic potential constants (/c3,/c4) and the anharmonicity constant (X) can be expressed as [24] X = 3/2k4_ -15/c|/4a> .…”

Section: Methods Of Calculationmentioning

confidence: 99%

Interpretation of Vapor-Liquid Frequency Shift of CH stretching vibration of chloroform and Fluoroform

Tóth

Jancsó

1991

Zeitschrift Für Naturforschung A

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Dedicated to Dr. Karl Heinzinger on the occasion of his 60th birthdayThe change in the frequency of the CH stretching vibration and in its anharmonicity constant, quadratic, cubic and quartic force constants and the equilibrium CH bond distance, on conden sation, were investigated by performing model calculations for liquid chloroform and fluoroform. The interactions between the hydrogen atom and the CH oscillator, represented by a Morse potential, and the halogen atoms of its neighbor molecules were described by the sum of LennardJones and Coulomb potential functions employed in molecular dynamics simulation. The calcula tions were carried out for different molecular arrangements in the liquid and have shown that mainly the size of the halogen atom, consequently the intermolecular distances, govern the direction of the CH vibrational frequency shift and of the change in the anharmonicity constant on the vapor-liquid transition. The pressure and temperature dependence of the CH stretching vibration was also studied for liquid chloroform. While the calculated pressure dependence is in good agreement with that observed, only the direction of the temperature dependence is in accordance with experimental observation.I n te r p r e ta tio n o f V a p o r-L iq u id F re q u e n c y S h ift

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Estimation of Anharmonic Potential Constants. II. Bent XY2 Molecules

Cited by 336 publications

References 24 publications

Anharmonic Force Field and Isotopic Relations of Ozone

Anharmonic Force Field and Isotopic Relations of Ozone

Molecular dynamics of a model S N1 reaction in water

Interpretation of Vapor-Liquid Frequency Shift of CH stretching vibration of chloroform and Fluoroform

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