# Align atoms with chembelow/chemabove (chemfig)

I am building the selegiline structure and for this I use \chembelow and \chemabove from the chemfig package. The problem is that I cannot align the hydrogens (H_2) with the carbon (C), that is, the hydrogen symbol (H) is exactly on/under the carbon atom and not aligned to the left.

I hope you can help me. Greetings.

\setchemfig{atom style={scale=.85},atom sep=2.5em}
\chemname{%
\chemfig{%
\chemabove{C}{H}(-[:150]\chemabove{C}{H_2}-[:210]*6(=-=-=-))(-[:30]CH_3)-[:270]N(-[:210]H_3C)(-[:330]\chembelow{C}{\;H_2}-[:30]C~[:30]CH)
}}%
{Selegiline}%

• Currently, the H_2 appears to be horizontally centered with respect to the C atom, but you mention not wanting them to be left aligned. Would you mind adding a sketch of the expected output? Is this closer to the expected alignment? i.stack.imgur.com/Fcaef.png Sep 23 at 19:28
• @leandriis That's right, I would like to get a structure like the one in i.stack.imgur.com/Fcaef.png, but I get this: i.imgur.com/V78fUd6.png (notice how hydrogen remains a little to the left with respect to carbon). Sep 23 at 19:41

## 2 Answers

a version showing all H, without using \chemabove or \chembelow

\setchemfig{atom style={scale=.85},atom sep=2.5em}
%
\chemname{\chemfig{C(-[2,.35,,,,draw=none]H)(-[:150]C(-[6,.35,,,,draw=none]H)(-[2,.35,,,,draw=none]H)-[:210]*6(=-=-=-))(-[:30]CH_3)-[:270]N(-[:210]H_3C)(-[:330]C(-[6,.35,,,,draw=none]H)(-[2,.35,,,,draw=none]H)-[:30]C~[:30]CH)}}
{Selegiline}
%


OR...

\setchemfig{atom style={scale=.85},atom sep=2.5em}
%
\chemname{\chemfig{C(-[2,.35,,,,draw=none]H)(-[:150]C(-[:70,.35,,,,draw=none]H_2)-[:210]*6(=-=-=-))(-[:30]CH_3)-[:270]N(-[:210]H_3C)(-[:330]C(-[:290,.37,,,,draw=none]H_2)-[:30]C~[:30]CH)}}
{Selegiline}
%


\documentclass[margin=5mm]{standalone}
\usepackage{chemfig}

\begin{document}

\setchemfig{atom style={scale=.85},atom sep=2.5em}
\chemname{%
\chemfig{%
\chemabove{C}{H}(-[:150]\Chemabove{C}{\phantom{_2}H_2}-[:210]*6(=-=-=-))(-[:30]CH_3)-[:270]N(-[:210]H_3C)(-[:330]\Chembelow{C}{\phantom{_2}H_2}-[:30]C~[:30]CH)
}}%
{Selegiline}%
\qquad
%
\chemname{%
\chemfig{%
(-[:150]-[:210]*6(=-=-=-))(-[:30]CH_3)-[:270]N(-[:210]H_3C)(-[:330]-[:30]~[:30]CH)
}}%
{Selegiline}%
\qquad
%
\chemname{%
\chemfig{%
(-[:150]-[:210]*6(=-=-=-))(-[:30])-[:270]N(-[:210])(-[:330]-[:30]~[:30])
}}%
{Selegiline}%

\end{document}

• Just what I was looking for. Thank you! Sep 23 at 21:05