rmgpy.kinetics.
Wigner
(frequency)¶A tunneling model based on the Wigner formula. The attributes are:
Attribute | Description |
---|---|
frequency | The imaginary frequency of the transition state |
An early formulation for incorporating the effect of tunneling is that of Wigner [1932Wigner]:
where \(h\) is the Planck constant, \(\nu_\mathrm{TS}\) is the negative frequency, \(k_\mathrm{B}\) is the Boltzmann constant, and \(T\) is the absolute temperature.
The Wigner formula represents the first correction term in a perturbative expansion for a parabolic barrier [1959Bell], and is therefore only accurate in the limit of a small tunneling correction. There are many cases for which the tunneling correction is very large; for these cases the Wigner model is inappropriate.
calculateTunnelingFactor
(self, double T) → double¶Calculate and return the value of the Wigner tunneling correction for the reaction at the temperature T in K.
calculateTunnelingFunction
(self, ndarray Elist) → ndarray¶Raises NotImplementedError
, as the Wigner tunneling model
does not have a well-defined energy-dependent tunneling function.
frequency
¶The negative frequency along the reaction coordinate.
[1932Wigner] | E.Wigner. Phys. Rev. 40, p. 749-759 (1932). doi:10.1103/PhysRev.40.749 |
[1959Bell] | R. P. Bell. Trans. Faraday Soc. 55, p. 1-4 (1959). doi:10.1039/TF9595500001 |