In the two column paper, if I have a long equation that I want to cover both columns, I use the following form, I would like to know if it is the correct way to do this:
\begin{figure*}[!t]
\normalsize
\begin{eqnarray} \label{eq:er12}
F = xxxxxxxx + xxxxx + ...
\end{eqnarray}
\hrulefill
\vspace*{2pt}
\end{figure*}