Bidentate Sticking Coefficients are incorrect

[ChrisBNEU]

I came across this comment in reacton.py.

# ToDo: missing the sigma terms for bidentate species. only works for single site adsorption

I think it is referring to the sigma shown here:

As far as I can tell, this comment is still correct. I don't think we have any families that would be affected by this, but I am bringing it up since we may be creating a lot more families soon. I think the the situation we would need it is if we have a gas phase species colliding with a bidentate species. The only reason we haven't added it in is because we haven't had a reaction to test it on.

Source for equation in pp 39, equation 56 in chemkin surface manual.
chemkin11surfacechemkin.pdf

[ChrisBNEU]

The reason I made a discussion is because I want to know:

• would excluding the sigma term cause any of our current families rates to be wrong?
• if it doesn't currently affect anything, should we try to fix this now or just wait till we need it for a new family?

[JacksonBurns]

Do we have a way to test it without already having a new family that would require it?

[bjkreitz]

I made a PR to fix this issue

[JacksonBurns]

See #2533