Update index.md
Small typo change.
@@ -112,7 +112,7 @@ Hundreds of organisations and packages are using *pydantic*, including:
[The Molecular Sciences Software Institute](https://molssi.org)
: are using *pydantic* in [QCFractal](https://github.com/MolSSI/QCFractal), a massively distributed compute framework
- for quantum chemsitry.
+ for quantum chemistry.
For a more comprehensive list of open-source projects using *pydantic* see the
[list of dependents on github](https://github.com/samuelcolvin/pydantic/network/dependents).
