Transition-State-Theory Rate Calculator

Convert computed activation thermochemistry into temperature-dependent rate constants with canonical Eyring transition-state theory. Barriers come from activation free energies or enthalpies and entropies, or from species Gibbs energies of reactants and transition states, referenced to an explicit standard state with the molecularity and reaction-path degeneracy you declare. An optional Wigner correction accounts for tunneling. Each k(T) table is fitted to two-parameter and modified Arrhenius forms, with fit-quality and validity warnings.
0 reactions and 0 species ready
Estimated minimum cost: $—

Examples

Reactions

One elementary step per row (up to 200), each with a unique reaction_id. Give activation thermochemistry directly as dg_act, or dh_act and ds_act, with an explicit molecularity. Or name reactants (for example CH4 + H) and a transition state ts from the species table below, and the barrier is taken as G(TS) − ΣG(reactants). Optional sigma is the reaction-path degeneracy, and imag_freq_cm1 is the transition-state imaginary frequency used for Wigner tunneling. Other columns are ignored.

or drop a file here

Species thermochemistry

Needed only for reactions defined by reactants and ts. Each row is a species_id with a Gibbs energy g, or an enthalpy h and entropy s. Absolute quantum-chemistry energies are fine; only differences enter the barrier. Add a t_k column with several rows per species to interpolate linearly in temperature; the temperature grid must stay inside each tabulated range. A single row per species is treated as temperature-independent.

or drop a file here

Temperature grid

Rate constants are evaluated at 3–500 temperatures between the bounds. Spacing that is uniform in 1/T suits Arrhenius fitting.