\begin{equation*}
\vec{\mu}^{(eq)}_2 = \begin{pmatrix}\rho \\
 \rho \ou \\
 \rho \ov \\
 \rho \ow \\
\rho( \ow^2   + \ov^2   + \ou^2   +3 c_s^2 )  \\
\rho( \ou^2   - \ov^2  ) \\
\rho( \ou^2   - \ow^2  ) \end{pmatrix}.
\end{equation*} 
