Hi,

I am running pyrolysis reactions on ReaxFF yet the reaction rate constants (k) I am obtaining are quite low (order of E-04) while our experimental results are much higher (order of E+05).

I am running the pyrolysis of propylene glycol (PG) as follows using NVT Berendsen method:

- equilibrate at 1000K for 10ps

- increase temperature to 3500K for 500ps

- fix temperature at 3500K for another 500ps

The simulation contains 10 molecules of PG in a 50*50*50 box.

I obtained the k values in two ways:

1. using ChemTraYzer which gives me many elementary reactions

2. using lnN - lnN0 = kt where N0 is original number of PG molecules, N is the number of PG molecules when the product forms at time t.

Both give me low k values. How should I proceed to let the values to similar to experimental results?

The experimental reaction does occur at lower temperatures (T= 433K to 933K) however when I interpolate the experimental Arrhenius constant and activation energy (A0 and Ea) to higher T, I still get higher experimental k values.