When an ethanol solution of dimethylglyoxime (DMG) is added to an ammoniacal solution of Ni(II), a rosy red precipitate of bis(dimethylglyoximato)nickel(II) is formed. In this complex, DMG acts as a bidentate ligand. The Ni(II) ion has a $d^8$ configuration, and in the presence of the strong field DMG ligand, the electrons pair up, resulting in $dsp^2$ hybridization. This gives the complex a square planar geometry, not tetrahedral. Furthermore, the complex is stabilized by symmetrical intramolecular hydrogen bonding between the oxygen and hydrogen atoms of the DMG ligands. Therefore, the statement that the red complex has a tetrahedral geometry is incorrect.