Neodymium interatomic distance

The single crystal X-ray structure of hydrated neodymium hypophosphate, NdHP206-4H20, has been determined.239 The Nd ion is eight-coordinated to four H20 and two bidentate hypophosphate anions. The details of interatomic distances and bond angles were compared with other members of this isostructural series, which extends at least from Nd to Er.240... 

X-ray diffraction studies on single crystals of NdFe oSiCo 5 have established its structure with the space group I4i/amd and Z = 4 formula units per unit cell. The positions of the neodymium, iron and silicon atoms correspond to the BaCdn structure. The positional and thermal parameters for NdFejoSiCo s of BaCdj, type structure have been given by Le Roy et al. (1987), as well as the interatomic distances in this compound. This structure is a disordered version of LaMnnC, 52 (Ross et al. 1981). Each neodymium atom is surrounded by a polyhedron of 26 atoms, i.e. 18 iron atoms, four carbon atoms and four atoms which may be iron or silicon. Fe(l) is surrounded by 14 atoms, Fe(2) by 13 atoms, and the (Fe-Si) site by 12 atoms. As has been pointed out, the carbon atoms fill octahedral voids formed by four iron atoms and two neodymium atoms, with an occupancy of 25%. 

A projection of the crystal structure of NdPs (Wichelhaus and von Schnering 1976) is shown in fig. 14. The CPs of all phosphorus atoms are distorted tetrahedra formed by neodymium and phosphorus atoms (fig. 14). Zigzag-Uke chains of phosphorus atoms are joined with one another by P3 atoms and form a fimnework. No Nd-Nd contacts occur in NdPs structure. Interatomic distances are riNd-p=0.3046-0.2991 5p p = 0.2211-0.2162. 

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