Refinement results

The population parameters of the 3(g) site are listed as g, i.e. they represent fractional occupancies by Ni and Sn, refined assuming full overall occupancy of the site. 

The following anisotropic displacement parameters are fixed by symmetry for all sites P13 = P23 = 0- 

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After return to the Commander window, the reaction retrieval may be executed separately 629 Dicls-Aldcr reactions between aliphatic dienes and cyclic dicno-pliiles are found. This partial result can be narrowed down by restricting tlie reaction conditions by means of the fact editor, The search field codes for the yield and the temperature can be found to be RX.NYD and RX.T, respectively, either by browsing the database structure or by applying the Find option, as described in the first example. To ensure that the retrieved reaction conditions belong to the same experiment, both search terms must be connected by means of the PROXIMITY operator. Before the retrieval is started, the option "Refine results in... 

Using the refinement parameters, electron density maps were calculated. Figure 1 shows an example derived from CU96. According to all refinement results the intensities of the strong reflections were too low. Therefore, they were omitted for the electron density studies. The problem is currently under study. Additionally, low-temperature measurements are planned for the near future. 

Refinement results in realistic deliverables for each development cycle depending on what development process is most suited to the project. 

The static model deformation density corresponding to the multipole refinement results is given by... 

It should be emphasized that the formyl group remained intact in major product 3 despite the reaction under forcing conditions. This is the first example of silylformylation in which a trialkylsilyl group and a formyl group are simultaneously connected to acetylenic carbons to form 1 in a one-pot reaction. Based on this breakthrough, the Matsuda group " published refined results and coined the word silylformylation . The reaction has since been applied to a variety of substrates as described in the following sections. 

By contrast to the /m3m refinement, the /43m refinement resulted in virtually no outstandingly bad disagreements between observed structure factors (obtained as defined above) and calculated ones. The powder line h2 + k2 + l2 = 34 is illustrative of the improvement of individual comparisons. 

Figure 8.5 ALBP refinement results. (a) Theoretical estimates of the rms positional errors in atomic coordinates according to Luzzati (1952) are shown superimposed on the curve for the ALBP diffraction data. The coordinate error estimated from this plot is 0.25 A with an upper limit of about 0.35 A. (b) Mean values of the main-chain and side-chain temperature factors are plotted versus the residue number. The temperature factors are those obtained from the final refinement cycles. Reprinted with permission from Z. Xu et al. (1992) Biochemistry 31,3484—3492. Copyright 1992 American Chemical Society.

Initial atom coordinates for the refinement were taken from single crystal data of related SAPO-34.5 For both as-synthesised materials it was essential to incorporate a template into the model otherwise the refinement was not stable. Thermal parameters were refined isotropically and no restrictions were used. Crystal data and refinement results of both as-synthesised materials are given in Table 1 and final Rietveld plots (crosses represent experimental points, solid line is calculated curve below is the difference vertical lines mark reflection positions) are presented on Figures 2 and 3. 

It should be emphasized that the calculation of the number of electrons described above is not exact since x-ray scattering factors are only directly proportional to the number of electrons at 20 = 0° and the proportionality becomes approximate at sinG/A, > 0. The population parameter(s) refinement results are usually more reliable in neutron diffraction because neutron scattering lengths are independent of the Bragg angle. 

Given the observed small variations in the Rietveld refinement results, it is much better to employ all available data while performing the combined least squares fit of the model. This can be done using the majority of available Rietveld refinement programs and is illustrated in the next section. 

The expected or experimentally assigned positions of transactinoids in the Mendeleev Periodic Table are shown in Table 1.1. The ground state electronic structures were obtained mostly by sophisticated relativistic calculations [10] their quantitative characteristics are being refined. Results of different authors may vary... 

Figure 1. Random walk traces recorded by Perrin [5] Three trajectories obtained by tracing a small grain of putty at intervals of 30sec. Using Einstein s relation between the macroscopic gas constant and the diffusion constant, Perrin found a quite accurate result for Avogadro s number. Refined results were successively obtained by Westgren and Kappler [7,8],...

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