Site assignment

The simulation starts usually from an initial configuration with lattice sites assigned spin values between 1 and 16 at random, although at lower... 

LiNi02 Stoichiometry, cationic site assignment in Lii-xNii+x02... 

Conjugation site assigned on basis of NMR comparison with Morphine. 

Site assignments for Fe and other cations can be made using structure refinements based upon X-ray diffraction studies, and that subject is well reviewed by other papers in this volume (Brigatti and Guggenheim, this volume Ferraris, this volume). 

The ODMR results have been reported by the Lehigh group [10-12]. ODMR has been studied for 4H, 6H and 15R polytypes. The results in 4H and 15R have been used to aid the site assignments for the ODMR in 6H. Hence, it is sufficient to summarize the results in this polytype. 

Another extensively investigated trivalent cation in apatites is Sb, because Sb-doped FAp acts as an activator in fluorescent-light tubes (e.g., Davis et al. 1971 Soules et al. 1971 Mishra et al. 1987 DeBoer et al. 1991 Moran et al. 1992). Rietveld XRD refinements of a FAp powder sample with 2.2 wt % Sb suggested that is ordered at the Ca2 site (DeBoer et al. 1991), consistent with the site occupancy deduced from excitation and emission spectra of Sb-doped ClAp and FAp (Davis et al. 1971 Soules et al. 1971). However, the same study on a different sample containing 3.1 wt % Sb did not find any evidence for substitution at the Ca2 site but suggested, on the basis of electron density maps, that the Sb ions occupy the (1/3,2/3,1/4) and (2/3,1/3,1/4) sites (DeBoer et al. 1991). Also, the Ca2 site assignment for Sb ions is not consistent with results from Sb Mossbauer (Mishra et al. 1987) or F and MAS NMR studies (Moran et al. 1992 see below). 

Fig. 5.10 Vibrational (SFG) spectrum of CO/Pt(l 11) with CO in solution. Peak position and site assignment o = 0.0 mV, = 400 mV vs Pd/H2 reference electrode, ssp polarization [103].

It is important to note that in this case of an unequivocal site assignment the line splitting (AHj j) was four times larger than could be explained by a classical dipole interaction with the Gd moment of 7 This is an especially clear proof for the presence of pseudodipolar or orbital contributions to the indirect interaction, even in intermetallic compounds containing only S-state lanthanide ions. 

DyCo3 X 4.2 X = 0, 0.3 X = Ni, Fe domain signals site assignment (3b, 18hi, 6c, 18h2), field depence Yoshie and Nakamura (1989b)... 

A detailed discussion of the current understanding of the mechanism of the Mizoroki-Heck reaction can be found in earUer chapters of this book and in several excellent reviews [7]. Two mechanistic pathways, typically termed neutral and cationic, have been proposed to account for the differences in reactivity and enantioselectivity observed in asymmetric Mizoroki-Heck cycUzations of unsaturated trillates and halides. These pathways differ in the degree of positive charge and the number of available coordination sites assignable to the palladium(II) intermediates of the catalytic cycle. Because catalytic asymmetric Mizoroki-Heck cyclizations are typically carried out with bidentate Ugands, these pathways will be illustrated with a chelating diphosphine Ugand. 

It should be remarked that without the aids of complementary DOR and 3QMAS measurements and DFT calculations, it would have been impossible to determine the CS and QC tensors for each oxygen site. In the same study, the authors used a three-dimensional parameters (djjo, Pq, Q) comparison of the experimental data with the QCC results for oxygen-site assignments and structural refinement. The authors found that subtle changes in... 

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