Add data struct for cloud chemistry species

[mattldawson]

Issue Type

Code Clean-up

Issue Description

Move data related to specific chemical species in the cloud chemistry code to a new struct.

Acceptance Criteria

• Cloud chemistry code in Cloud chemistry module review #5 is modified to use a new chemical species struct whenever species-specific data is needed

Ideas

• Possible data members might include: molecular weight, density, Henry's Law parameters, or any variable that is labelled as being specific to a chemical species.
• If it makes sense, having simple functions (like calculation of the Henry's Law constant from species-specific parameters) on the new struct might be useful

blocked until renaming is completed

Will this change answers?

Yes

Will you be implementing this yourself?

Yes