The package provides an environment MOdiagram and some commands, to create molecular orbital diagrams using TikZ. For example, the MO diagram of dihydrogen would be written as:

\begin{MOdiagram}
  \atom{left}{ 1s = {0;up} }
  \atom{right}{ 1s = {0;up} }
  \molecule{ 1sMO = {1;pair, } }
\end{MOdiagram}

The package also needs the l3kernel and l3packages bundles from the LaTeX 3 experimental distribution.

The author is Clemens Niederberger. The package is Copyright © 2011-2013 Clemens Niederberger.