材料期刊网

The local structure for NiSiF(6)center dot 6H(2)O crystal has been investigated by diagonalizing the complete energy matrices, By simulating the EPR and optical spectra, the local structure parameter theta(0) = 54.8901 is determined at room temperature and is different from theta(0)' = 55.0899 obtained by X-ray diffraction experiment, suggesting that: (i) the H(+) ions lead to a deviation of the equivalent position of effective charge of H(2)O molecule from O(2) ion, (ii) the neighboring [siF(6)](2) octahedral clusters lead to a deflection of the H(2)O molecules towards them. The deviation angle Delta theta(0) = -0.1999 is reported for file first time. Furthermore, the local structure NiSiF(6)center dot 6H(2)O crystal has been determined it 4.2 and 77 K. (c) 2007 Elsevier B.V. All rights reserved.