The package provides the command \chemfig{<code>}, which draws
molecules using the TikZ package. The <code> argument provides
instructions for the drawing operation. While the diagrams
produced are essentially 2-dimensional, the package supports
many of the conventional notations for illustrating the
3-dimensional layout of a molecule. The package uses TikZ for
its actual drawing operations.

Homepage:
https://ctan.org/pkg/chemfig
