Thiocyanate is a rigid linear anion. The key contrasts in the structural chemistry between the atomic halides anion and linear thiocyanate arise therefore from the additional degrees of freedom introduced by moving from a sphere to a rod. The most important new degree of freedom is the orientation of the NCS - ligand. This can be parameterized by the M-N-C and M-S-C angles for a bridging thiocyanate ligand. As thiocyanate is stiff, the intramolecular degrees of freedom are less important, and deviations from linearity and variations in the bond lengths (despite the two distinct resonance structures) are typically small. The orientation of NCS -is so important for the chemistry of thiocyanate because of the different bonding preferences of the N-