However, if you search on Google:
"Property Prediction for Butane" site:https://www.chemeo.com
Interesting, it looks like they massively dropped these pages from the index (or at least, from what they return as results) this is great (if they are not dropping other important pages)!
you could add an additional URL parameter via pushState and ensure that you're defining the canonical tag only to the main data pages. You could also define the new parameter in webmaster tools and tell googlebot to ignore it
For example this URL:
https://www.chemeo.com/predict?smiles=CCCC
is performing the drawing of the molecule using RaphaelJS, then pulling the corresponding molecule from the database using Ajax and updating the page. Googlebot is performing all the steps perfectly well to add the end index the page.
It is very annoying because this is not important in our case, what we want is the good indexing of the main data pages, not these pages... I do not want to block the bot yet, but I need to figure out a way to have the main page better ranked.