ChemRxiv is an open access database containing unpublished preprints in chemistry and related areas. It was established in 2017 by the American Chemical Society in collaboration with several partners including the Royal Society of Chemistry and German Chemical Society.
MSN covers the mathematical sciences literature, including computational chemistry and mathematical physics. It contains more than 3 million references dating back to the early 1800s. It is produced by the American Mathematical Society (AMS).
The largest public patent database on the internet, Espacenet contains 100 million patent documents from more than 90+ countries including Canada and the U.S., plus 2 million records for non-patent literature cited in EPO search reports. Espacenet is produced by the European Patent Office (EPO).
The official database of the World Intellectual Property Organization (WIPO). Explore 100 million patent documents from more than 75 regional and national patent offices. Major national collections include Canada, China, European Patent Office, Japan, Korea, Russia, the U.K and U.S.
SureChemBL is a public chemical patent database maintained by the European Bioinformatics Institute (EBI). It indexes chemical structures from full-text EP, JP, US and WO patent documents; bibliographic data from more than 90 countries is also searchable.