Drawing molecular orbital diagrams and atomic orbitals

A molecular orbital (MO) diagram describes chemical bonding in molecules and displays energy levels. First, we will create such an MO diagram, and then we will draw atomic orbitals with a more visual approach.

How to do it...

We will use the tikzorbital package written by Germain Salvato-Vallverdu. These are the steps:

1. Start with any document class; we choose the standalone class here. Then load the tikzorbital package that implicitly loads TikZ:

   \documentclass[border=10pt]{standalone}
   \usepackage{tikzorbital}

2. Load the positioning and quotes TikZ libraries and begin the document:

   \usetikzlibrary{positioning,quotes}
   \begin{document}

3. Open a tikzpicture environment, and define a custom ^ style to get small, center-aligned sans-serif text where we want it:

   \begin{tikzpicture}[note/.style =
     {align = center, font = \sffamily\scriptsize}]

4. Use the \drawLevel command to draw an energy level line, that...