# I am using twocolumn svjour3 template to submit a paper. I want to write long equations as a single column. But I get an error message

Here's what I did: I have the same problem with long equations in the svjour3 document class. I want to display the long equations as a single column. I tried

\documentclass[twocolumn]{svjour3}          % twocolumn
\usepackage{widetext}
\begin{document}

\begin{widetext}
\begin{eqnarray}
%long equation here
\end{eqnarray}
\end{widetext}

\end{document}


but I get the error message:

! LaTeX Error: Environment widetext undefined.


 Welcome to TeX.SX. A tip: If you indent lines by 4 spaces, then they're marked as a code sample. You can also highlight the code and click the "code" button ({}) or select your code and hit Ctrl+K. – Claudio Fiandrino Feb 22 at 8:01