$$ M= \begin{pmatrix} -\sin 0 & -\sin \frac{2\pi}{3} & -\sin -\frac{2\pi}{3}\ \cos 0 & \cos \frac{2\pi}{3} & \cos -\frac{2\pi}{3}\ \frac{1}{3} & \frac{1}{3} & \frac{1}{3} \end{pmatrix}= \begin{pmatrix} 0 & -\frac{\sqrt{3}}{2} & \frac{\sqrt{3}}{2}\ 1 & -\frac{1}{2} & -\frac{1}{2}\