Figure and table, side by side

Question

So I tried

\begin{figure}[!tbp]
  \centering
\begin{minipage}[b]{0.4\textwidth}
\includegraphics[width=1\textwidth]{configuration}
\caption{Nearest-neighbour marginals for minimal 5-qubit configurations}
\label{fig:5qbconf}
\end{minipage}
\hfill
\begin{minipage}[b]{0.4\textwidth}
\begin{table}
\begin{tabular}{|c|c|c|}
\hline
\multicolumn{1}{|c|}{\textbf{\large Configuration \hspace{0.1cm} }} &           \multicolumn{1}{c|}{\textbf{\large \hspace{0.2cm} $ \Tr[\rho W] $ \hspace{0.2cm} }} &   \multicolumn{1}{c|}{\textbf{\large \hspace{0.1cm}  Pure \hspace{0.1cm}      }}\tabularnewline
\hline
\hline
\multicolumn{3}{|c|}{\textbf{4-Qubit Configurations}}\tabularnewline
\hline
\hline
 \includegraphics[scale=0.5]{4qb_1} & $-3.15 \cdot 10^{-3}$ & No \tabularnewline
\hline
 \includegraphics[scale=0.5]{4qb_2} & $-3.56\cdot 10^{-3}$ & Yes\tabularnewline
\hline
\hline
\multicolumn{3}{|c|}{\textbf{5-Qubit Configurations}}\tabularnewline
\hline
\hline
\includegraphics[scale=0.5]{5qb_1} & $-1.13 \cdot 10^{-3}$ & Yes\tabularnewline
\hline
\includegraphics[scale=0.5]{5qb_2} & $-1.31 \cdot 10^{-3}$ & Yes\tabularnewline
\hline
\includegraphics[scale=0.5]{5qb_3} & $-1.38 \cdot 10^{-3}$ & Yes\tabularnewline
\hline
\hline
\multicolumn{3}{|c|}{\textbf{6-Qubit Configurations}}\tabularnewline
\hline
\hline
\includegraphics[scale=0.5]{6qb_1} & $-2.01 \cdot 10^{-4}$ & Yes\tabularnewline
\hline
\includegraphics[scale=0.5]{6qb_2} & $-2.56 \cdot 10^{-4}$ & Yes\tabularnewline
\hline
\includegraphics[scale=0.5]{6qb_3} & $-2.92 \cdot 10^{-4}$ & Yes\tabularnewline
\hline
\includegraphics[scale=0.5]{6qb_4} & $-3.80 \cdot 10^{-4}$ & Yes\tabularnewline
\hline
\end{tabular}
\captionof{table}{Tested states with various configurations. All states are uniquely determined by their known two-body nearest-neighbour marginals.}
\end{table}
\end{minipage}
\end{figure}

and, upon compiling I get a "Not in outer par mode" error. Any ideas how I can do this?

Answer 1

You can't have one float (table) inside another float (figure), which is why you get the error. But you don't need the table environment to use a tabular, so just remove \begin{table} and \end{table} and your code should work (assuming there are no other errors there, I haven't tested).