From 248874de830368f4960d7086366768723ae9eef5 Mon Sep 17 00:00:00 2001 From: Ray Speth Date: Wed, 11 May 2016 14:45:36 -0400 Subject: [PATCH] [Doc] Add description of sticking reaction parameterization --- doc/sphinx/cti/reactions.rst | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/doc/sphinx/cti/reactions.rst b/doc/sphinx/cti/reactions.rst index c78048087..fe62a3d4d 100644 --- a/doc/sphinx/cti/reactions.rst +++ b/doc/sphinx/cti/reactions.rst @@ -456,6 +456,37 @@ used:: coverage=[['H(S)', a_1, m_1, E_1], ['PT(S)', a_2, m_2, E_2]])) +Sticking Coefficients +--------------------- + +Collisions between gas-phase molecules and surfaces which result in the gas- +phase molecule sticking to the surface can be described as a reaction which is +parameterized by a sticking coefficient: + +.. math:: + + \gamma = a T^b e^{-c/RT} + +where :math:`a`, :math:`b`, and :math:`c` are constants specific to the +reaction. The values of these constants must be specified so that the sticking +coefficient :math:`\gamma` is between 0 and 1 for all temperatures. + +The sticking coefficient is related to the forward rate constant by the +formula: + +.. math:: + + k_f = \frac{\gamma}{\Gamma_\mathrm{tot}^m} \sqrt{\frac{RT}{2 \pi W}} + +where :math:`\Gamma_\mathrm{tot}` is the total molar site density, :math:`m` is +the sum of all the surface reactant stoichiometric coefficients, and :math:`W` +is the molecular weight of the gas phase species. + +A reaction of this form can be written as:: + + surface_reaction("H2O + PT(S) => H2O(S)", stick(a, b, c)) + + Additional Options ==================