Structure factor data

Studying the temperature dependence of structure factor data as shown in Fig. 24, Bartelt et also extract effective exponent estimates for y, and V, working in the limits k < 1 and using Eq. (57). They find that above the exponents are within of order 10% of their expected values, while below reliable estimates are more difficult to obtain. This work gives some justification for the notion of identifying with the inflection point of the... 

In Fig. 3.16 dynamic structure factor data from a A =36 kg/mol PE melt are displayed as a function of the Rouse variable VWt (Eq. 3.25) [4]. In Fig. 3.6 the scaled data followed a common master curve but here they spht into different branches which come close together only at small values of the scahng variable. This splitting is a consequence of the existing dynamic length scale, which invalidates the Rouse scaling properties. We note that this length is of purely dynamic character and cannot be observed in static equilibrium experiments. 

Vaguine, A. A., RicheUe, J. and Wodak, S. J. (1999). SFCHECK a unified set of procedures for evaluating the quahty of macromolecular structure-factor data and their agreement with the atomic model. Acta Crystallogr. D 55,191-205. 

Structure Factor Data. Only Yokouchi et al include a structure factor set in their published paper Mencik offered sets by application to the author. Because of the large amount of data, values will not be reproduced here. The set of Hall and... 

In 1995, an elaborated method was developed for accurate structure analysis using X-ray powder diffraction data, that is, the MEM/Rietveld method [1,9]. The method enables us to construct the fine structural model up to charge density level, and is a self-consistent analysis with MEM charge density reconstruction of powder diffraction data. It also includes the Rietveld powder pattern fitting based on the model derived from the MEM charge density. To start the methods, it is necessary to have a primitive (or preliminary) structural model. The Rietveld method using this primitive structural model is called the pre-Rietveld analysis. It is well known that the MEM can provide useful information purely from observed structure factor data beyond a presumed crystal structure model used in the pre-Rietveld analysis. The flow chart of the method is shown in Fig. 2. 

There is a variety of software that can be used to process pseudo-single crystal experimental diffraction data represented in a form of individual structure factors or their squares (consult http //www.iucr.org and/or http //www.ccpl4.ac.uk). The most commonly used software products are SHELXS-90 and SHELXL-97 (author G.M. Sheldrick), which are distributed free for academic use (consult SHELX home page at http //shelx.uni-ac.gwdg.de/SHELX/index.html for details). Unless noted otherwise, processing of the individual structure factor data, direct phase determination, Patterson-, Fourier- and E-map calculations shown in this chapter were performed using WinCSD software, which is available from STOE Cie, Gmbh (http //www.stoe.com/products/index.htm). 

A thorough investigation of simulated structure factor data of ammonia provides us with quantitative figures for the accuracy of BCP properties achievable with the pseudoatom projection [72]. The Pbcp> Pbcp> tBCp(H) indices of the static model density obtained by the multipole refinement of HF/6-31IG static structure factors deviate from the correct values (derived... 

FIGURE 14.16 Guinier analysis of structure factor data in Figure 14.15. By Equation 14.53 I vs. yields straight lines with slope... 

This reduced partial structure factor analysis was also applied to the isotactic polymer. For surface concentrations less than 0.8 mgm a uniform layer model fitted the partial structure factor data for the spread polymer very well. Above this value, a Gaussian partial structure factor model fitted best however, even though the standard deviations of the Gaussians were reasonably large, the surface concentrations calculated from the parameters of the distribution were still less than the amount dispensed. This was again taken as evidence that some of the polymer penetrates the sub-phase and becomes lost insofar as the... 

We note the following points regarding the structure factor data ... 

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