Editing Cheminformatics (section)

=== Virtual libraries ===
{{primary sources|section|date=February 2020}}
Chemical data can pertain to real or virtual molecules.  Virtual libraries of compounds may be generated in various ways to explore chemical space and hypothesize novel compounds with desired properties. Virtual libraries of classes of compounds (drugs, natural products, diversity-oriented synthetic products) were recently generated using the FOG (fragment optimized growth) algorithm.<ref>{{cite journal|title=FOG: Fragment Optimized Growth Algorithm for the de Novo Generation of Molecules occupying Druglike Chemical | last=Kutchukian | first=Peter  |author2=Lou, David |author3=Shakhnovich, Eugene  |journal=Journal of Chemical Information and Modeling | year=2009 |volume=49 | pages=1630–1642|doi=10.1021/ci9000458|pmid=19527020|issue=7 }}</ref>  This was done by using cheminformatic tools to train transition probabilities of a [[Markov chain]] on authentic classes of compounds, and then using the Markov chain to generate novel compounds that were similar to the training database.