Figure18

Figure 18. Anisotropy of relative thermal vibrations determined by EXAFS in Na: GaFe(CN)$${}_6$$ (top panels) and TiCo(CN)$${}_6$$: 2H$${}_2$$O (bottom panels) for the M-N bonds (left panels) and for the M'-C bonds (right panels). The insertion of guest Na$${}^{+}$$ ions or H$${}_2$$O molecules hinders the transverse atomic vibrations, thus inhibiting the NTE. The effect is much more pronounced for the M-N bonds than for the M'-C bonds. Figure taken from Refs.^{[117, 118]}. © ACS Publishing. Reproduced with permission. All rights reserved.