RETRIEVAL/SEARCH:

THOR:

Lookup by exact reaction.

Lookup by molecule as Reactant, Product, Agent.

Lookup a reaction by both reactant(s) and product(s). That is, find all reactions with molecule(s) as reactant and with molecule(s) as product.

Merlin:

Super/sub-structure searches (atom-map used if available). Use structural fingerprint for a screen.

Reaction, molecule similarity. Use structural fingerprint or difference fingerprint.