Hindered internal rotation in molecular systems: quantum statistics of equilibrium and rate constants in the Wigner function formalism

Vojta, G.; Zylka, Christian

doi:10.1007/bf01122434

Cited by 2 publications

(2 citation statements)

References 23 publications

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“…Ellingson et al (2006) calculated the torsional partition function ratio for D 2 O 2 /H 2 O 2 by using several approximations. They suggested that the Wigner-Kirkwood approximation (Vojta and Zylka, 1993) best described the studied isotope effects which gave the HIR for b(D 2 O 2 /H 2 O 2 ) as about 0.990 at 300 K. If this value is correct, then the hindered internal rotation should be much less important than the anharmonicity of ZPE to b factor which is about 0.903 based on our calculation (the shift of total ZPEs in our calculation is very similar to the accurate value from Koput et al (2001), both are about 1400 cm À1 ). Unfortunately, there is no good experimental way to precisely determine the isotopic effects of hindered internal rotation.…”

Section: Isotope Partition Function Ratios For Corrections Beyond Harmentioning

confidence: 99%

On the proper use of the Bigeleisen–Mayer equation and corrections to it in the calculation of isotopic fractionation equilibrium constants

Liu

Tossell

Liu

2010

Geochimica et Cosmochimica Acta

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Section: Isotope Partition Function Ratios For Corrections Beyond Harmentioning

confidence: 99%

On the proper use of the Bigeleisen–Mayer equation and corrections to it in the calculation of isotopic fractionation equilibrium constants

Liu

Tossell

Liu

2010

Geochimica et Cosmochimica Acta

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“…In this method, the partition function consists of a classical term and a quantum correction. The latter is obtained by expanding Equation () in powers of

ℏ

q_{HR}^{MPG} goodbreak= q_{class}^{WK} ((), \frac{q_{HO}}{q_{CHO}^{WK}}),

q_{CHO}^{WK} = \frac{k_{B} T}{h ν} - \frac{h ν}{24 k_{B} T},

q_{class}^{WK} goodbreak= q_{FR} e^{- V_{0} / 2 italicRT} ([], I_{0} ((), V_{0} / 2 italicRT) goodbreak- ((), \frac{π V_{0}}{24 {italicRTq}_{italicFR}^{2}}) I_{1} ((), V_{0} / 2 italicRT)),

where

q_{class}^{WK}

and

q_{CHO}^{WK}

are the classical first‐order Wigner–Kirkwood and classical HO partition functions, respectively; and

I_{1}

is the modified Bessel function of the first type of first order 44 .…”

Section: The Hindered Rotor Partition Function For Gasesmentioning

confidence: 99%

The hindered rotor theory: A review

Dzib

Merino

2021

WIREs Comput Mol Sci

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Hindered rotations are common in nature and can greatly affect thermodynamic properties. Typically, the standard rigid-rotor harmonic-oscillator approximation is used to compute thermodynamic properties; however, it often leads to serious errors, particularly for molecules with hindered rotations. Hence, to reach accurate thermodynamic predictions for such cases, the hindered rotor approximation must be applied. Different methods to compute thermodynamic properties for molecules with hindered rotations are available. Herein, we review the theoretical basis of different methods, their accuracy, and applicability. We also present the different algorithms to identify hindered rotors and obtain the input parameters for the hindered rotor model, and the software available to compute thermodynamic properties under this scheme.

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Hindered internal rotation in molecular systems: quantum statistics of equilibrium and rate constants in the Wigner function formalism

Cited by 2 publications

References 23 publications

On the proper use of the Bigeleisen–Mayer equation and corrections to it in the calculation of isotopic fractionation equilibrium constants

On the proper use of the Bigeleisen–Mayer equation and corrections to it in the calculation of isotopic fractionation equilibrium constants

The hindered rotor theory: A review

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