Chemfig is drawing out of the box, on my text

Question

I'm trying to make a figure to show hydrogen bounds. But the figure, draw using chemfig and tikz, but the figure overlaps the surrounding text.

Here is my MWE:

\documentclass{article}
\usepackage{chemfig}
\usepackage{lipsum}

\begin{document}
\lipsum[10]


\begin{figure}[h]
\centering
\begin{tikzpicture}
  \schemestart
  \draw (0,0) node {\chemfig{H-@{doublet}\charge{[circle]270=\|,340=\|}{O}-[:75]H}}
   (340:3) node [rotate=-20] {\chemfig{{@{hydrogene}H-\charge{[circle]270=\|,340=\|}{O}-[:75]H}}};
  \schemestop
  \chemmove{\draw [dashed,-] (doublet.340)--(hydrogene.160);}
\end{tikzpicture}
\caption{Schématisation d'une liaison hydrogène dans l'eau}
\label{fig:liaisonH}
\end{figure}

\lipsum[1]

\end{document}

As the chemfig/tikz code is obviously not perfect, any help to improve it is welcome. My primary concern is about the overlap between the figure and the text.

Edit: I found an unsatisfaying way to get it right: I added \vspace{1cm} before the picture and the caption. And then it almost looks like what I want: I would prefer: the figure centered, and if someone wants to correct the figure, the dashed line should go from O to H.

Answer 1

Since the combination of a tikz enviroment with \schemestart and \chemove seem to cause the problem, I simply added an invisible arrow and removed your nodes (they were not necessary).

The figure is now centered and the dashed line goes from the O to H molecule.

You can adjust the angle between the two molecules as you please by changing the value in \setchemfig{arrow angle=<value>} and the distance by changing the value in \arrow{0}[,<value>].

\documentclass{article}
\usepackage{chemfig}
\usepackage{lipsum}


\begin{document}
    \lipsum[10]
    

\begin{figure}[h]
    \centering
        \setchemfig{arrow angle=-5}
        \schemestart
        \chemfig{H-@{doublet}\charge{[circle]270=\|,340=\|}{O}-[:75]H}  
        \arrow{0}[,2.5] 
        \chemfig{{@{hydrogene}H-\charge{[circle]270=\|,340=\|}{O}-[:75]H}}
        \schemestop
        \chemmove{\draw [dashed,-] (doublet.340)--(hydrogene.160);}
    \caption{Schématisation d'une liaison hydrogène dans l'eau}
    \label{fig:liaisonH}
\end{figure}


\lipsum[10]

\end{document}

Answer 2

you can make the job easier if you create a separate figure for the molecules and then insert the figure into the text. In this way, the overlap between figure and text will not occur.

\documentclass[margin={2mm 2mm}]{standalone}
\usepackage{chemfig}

\begin{document}

\schemestart
            \chemfig{H-\charge{344=\|, 254=\|}{O}(-[:76]H)-[:344,3,,,,dotted]H-\charge{344=\|, 254=\|}{O}(-[:76]H)}
\schemestop

\end{document}