Drawing molecules

In the previous recipe, we already encountered formulae for molecules. Now let's see how to draw them. This means drawing a group of atoms and connecting them by lines of various kinds.

How to do it...

This rather complex seeming task becomes manageable using the chemfig package. It provides a compact syntax for drawing molecules. Let's draw some:

1. Start with any document class:

   \documentclass{article}

2. Load the chemfig package:

   \usepackage{chemfig}

3. Let's write molecules in a table. For this, we stretch the rows a bit and start a tabular environment with a right-aligned column and a left-aligned one.

   \renewcommand{\arraystretch}{1.5}
   \begin{tabular}{rl}

4. For molecules, use the \chemfig command. Write atoms as letters and a single bond using a dash:

     Hydrogen: & \chemfig{H-H} \\

5. Write a double bond using an equal-to sign:

     Oxygen:   & \chemfig{O=O} \\

6. For a triple bond, use a tilde:

     Ethyne:   & \chemfig{H-C~C-H}

7. End the table, and leave some space:

   \end{tabular...