Highly Resolved Spin-Density Distribution in the Prussian-Blue Precursors Cs2K[Fe(CN)6] and Cs2K[Mn(CN)6]

In magnetic materials of the Prussian‐blue type, what proportion of the unpaired electrons in the simple hexacyanometalate moves from the metal (red) to the carbon (gray) and nitrogen (green) atoms? Based on the solid‐state 13C and 15N NMR spectra, the amount, the sign, and the shape of the spin densities can be distinguished for axial and equatorial CN ligands. There is surprisingly little spin on the N atoms.