There already are tags here for reaction-mechanism but sometimes we might want to ask how an effect is achieved from a chemical that don't involve a chemical reaction.
For example, I just asked a question about Liquid crystals where the key issue was to understand how the chemical structures enable selective alteration of the polarisation of light when the orientation of the molecules is affected by a an electric field.
So I wanted to suggest a tag mechanism but that doesn't exist and, on reflection, is perhaps too general.
So what would be a good new tag for this sort of question? Should it be physical-mechanism or effect? or something else?