Zero length bond in chemfig?

Question

As you can clearly see in the high quality diagram above, I'm looking for a way to get the nitrogen and hydrogen bonded like that in chemfig.

Answer 1

You're looking for \chemabove{<atom>}{<above>}:

\documentclass{article}
\usepackage{chemfig}

\begin{document}

\chemfig{R^1-[:30]\chemabove{N}{H}-[:-30]R^2}

\end{document}

Just for the record: there's also \chembelow{<atom>}{<below>}. I've described them in a little more detail in my answer to “Changing space between atoms in Chemabove”