There are (obviously) a lot of chemical compounds. Wikipedia is able to translate names to molecular formulas for a lot of them.

But is there a way to enter a molecular formula and find the chemical's name?

Coming from the computer science background, I realize that there should be some canonical textual representation of the molecular formulas for such search to be possible. So is there a language that can represent a full formula, including the structure? I could only find some latex-based languages.

  • $\begingroup$ recent related chemistry.stackexchange.com/questions/74646/… $\endgroup$
    – Mithoron
    Commented May 16, 2017 at 22:58
  • 2
    $\begingroup$ So, SMILES or even better SMARTS $\endgroup$
    – Mithoron
    Commented May 16, 2017 at 23:00
  • $\begingroup$ chemistry.stackexchange.com/questions/34563/… $\endgroup$
    – Mithoron
    Commented May 16, 2017 at 23:05
  • 5
    $\begingroup$ chemspider.com has both a molecular formula search and a structural formula search. $\endgroup$ Commented May 17, 2017 at 2:43
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    $\begingroup$ I like chemspider.com. I wish such search was also integrated into the wikipedia. Unfortunately, wikipedia doesn't use chemical formulas in SMILES format for anything. $\endgroup$
    – Flying Jay
    Commented May 17, 2017 at 16:31

1 Answer 1


This answer is meant to address your second question about computerized representations of molecule structure since comments have already addressed your first question.

To truly represent the structure, mol and sdf formats are common: https://en.wikipedia.org/wiki/Chemical_table_file

Common string representations include SMILES and InChI. An issue with smiles is that there are multiple valid ways to represent a given molecule, which means a simple string match is not a good test for sameness. Canonical SMILES and InChI attempt to address this issue via additional rules. InChI additionally provides a standard way to convert the sometimes very long InChI strings into 27 character hashed version called InChIKey, which are better for searching.

Example Acetoin
SMILES string: CC(C(=O)C)O
InChI string: InChI=1S/C4H8O2/c1-3(5)4(2)6/h3,5H,1-2H3


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