It depends on many parameters, like the history of the material, whether NEG is activated or not, bakeout time and temperature. Put the outgassing rates of the bulkmaterial under the film, assuming it's baked and very clean. The simulation will be less ensitive to these numbers as most of the outgassing will be absorbed locally before propagating to adjacent locations.
The sticking factors also largely depend on NEG saturation level and the gas type. You can have a look at values I used when simulating a crotch absorber of the MAX-IV light source in my thesis (which you find on Google).