Problems using widetext.sty

Question

I need to prepare a document for a journal and I'm using the twocolumn option in the article class. Now I have a horrible equation that makes use of the cases environment so it's hard to split up to make it fit into one column. I do not want to use the figure* environment because I have no control over where to put the equation.

What I want to do is to use the widetext package and make sure that this equation looks something like it would like when one uses revtex4. However, when compiling my document I get an error, namely "improper \prevdepth". Does anyone have a clue what I have to do here?

A minimum working example (using the actual formula)

\documentclass[twocolumn]{article}
\usepackage{widetext}
\usepackage{flushend}
\usepackage{cuted}

\begin{document}

a lot of text ...


Here
\begin{widetext}
\begin{eqnarray} \label{e27}
T_{nn''}^{mm''}=({-}1)^{p-p''}\,\dil_0^{\infty}\,J_{m-m''}(au)\,J_{n''}(bu)\,J_{n+1}(u)\,du~=
\begin{cases}
& \dfrac{(q{+}p'')!\,(p{-}p'')!}{(q{-}q'')!\,(p{+}q'')!}\,a^{m-m''}b^{n''}\,P_{p-p''}^{(m-m'',n'')}(1{-}2A^2)P_{p-p''}^{(m-m'',n'')}(2B^2{-}1)~~~ \\ & \text{when}~~~n-n''\geq m-m''\geq0~,\\
\\
& \dfrac{(p{+}q'')!\,(q{-}q'')!}{(p{-}p'')!\,(q{+}p'')!}\,a^{m''-m}b^{n''}\,P_{q-q''}^{(m''-m,n'')}(1{-}2A^2)\,P_{q-q''}^{(m''-m,n'')}(2B^2{-}1)~~~ \\ & \text{when}~~~ n-n''\geq m''-m\geq0~, \\
\\
&0 ~~~ \text{otherwise}.
\end{cases}
\end{eqnarray}
\end{widetext}

a lot more text....
\end{document}

Any help would be greatly appreciated!

Answer 1

This works:

\documentclass[twocolumn]{article}
\usepackage{amsmath}
\usepackage{widetext}
\usepackage{flushend}
\usepackage{cuted}

\begin{document}

a lot of text ...

Here
\begin{widetext}
\begin{equation} \label{e27}
\begin{aligned}
&T_{nn''}^{mm''}=({-}1)^{p-p''}\,d_0^{\infty}\,J_{m-m''}(au)\,J_{n''}(bu)\,J_{n+1}(u)\,du = \\
&\qquad\begin{cases}
& \dfrac{(q{+}p'')!\,(p{-}p'')!}{(q{-}q'')!\,(p{+}q'')!}\,a^{m-m''}b^{n''}\,P_{p-p''}^{(m-m'',n'')}
(1{-}2A^2)P_{p-p''}^{(m-m'',n'')}(2B^2{-}1) \\ 
& \text{when}~~~n-n''\geq m-m''\geq0~,\\
\\
& \dfrac{(p{+}q'')!\,(q{-}q'')!}{(p{-}p'')!\,(q{+}p'')!}\,a^{m''-m}b^{n''}\,P_{q-q''}^{(m''-m,n'')}
(1{-}2A^2)\,P_{q-q''}^{(m''-m,n'')}(2B^2{-}1)~~~ \\ 
& \text{when}~~~ n-n''\geq m''-m\geq0~, \\
\\
&0\text{ otherwise}.
\end{cases}
\end{aligned}
\end{equation}
\end{widetext}

a lot more text....
\end{document}

The version used of widetext.sty has been downloaded from

https://svn.einsteintoolkit.org/documents/Paper_EinsteinToolkit_2010/widetext.sty