HighScore with the Plus option (HighScore Plus) is the commercial powder diffraction analysis software from PANalytical. It has been in constant development over the last 13 years and has evolved into a very complete and mature product. In this paper, we present a brief overview of the suite focusing on the latest additions and its user-friendliness. The introduction briefly touches some basic ideas behind HighScore and the Plus option.

The practical use of the average and difference intensities of Friedel opposites at different stages of structure analysis has been investigated. It is shown how these values may be properly and practically used at the stage of space-group determination. At the stage of least-squares refinement, it is shown that increasing the weight of the difference intensities does not improve their fit to the model. The correct form of the coefficients for a difference electron-density calculation is given. In the process of structure validation, it is further shown that plots of the observed and model difference intensities provide an objective method to evaluate the fit of the data to the model and to reveal insufficiencies in the intensity measurements. As a further tool for the validation of structure determinations, the use of the Patterson functions of the average and difference intensities has been investigated and their clear advantage demonstrated.

The algebraic modelling languages (AML) have gained wide acceptance and use in MathematicalProgramming by researchers and practitioners. At a basic level, stochastic programming models can be defined using these languages by constructing their deterministic equivalent. Unfortunately, this leads to very large model data instances. We propose a direct approach in which the random values of the model coefficients and the stage structure of the decision variables and constraints are "overlaid" on the underlying deterministic (core) model of the SP problems. This leads not only to a natural definition of the SP model: the resulting generated instance is also a compact representation of the otherwise large problem data. The proposed constructs enable the formulation of two stage and multistage scenario based recourse problems, as well as chance constrained problems. This design is presented as a stochastic extension of the AMPL language which we call SAMPL.

Librational motion within a crystal structure distorts the measured bond distances and angles from their physical values. TLS analysis of a rigid molecule or a rigid part of a molecule allows the calculation of bond‐length and angle corrections. Until now, no estimate of the error on these corrections has been available. A method is presented for propagating the errors on the anisotropic displacement parameters (ADPs) to the bond‐length and angle corrections which are a function of the libration tensor. The numerical significance of approximations made during the calculation is discussed.

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One of the requirements for the next generation of small‐molecule crystallographers is a mathematical programming infrastructure. It should provide a modelling design process, where the model formulation is kept separate from the optimization process to provide gains in reliability, scalability and extensibility, enabling the application of optimization components in general, and refinement‐based applications in particular, as applied to crystallographic problems. A research project has been undertaken to design and implement an innovative toolkit library – a small‐molecule toolkit (SMTK) – for crystallographic modelling and refinement. This paper provides an overview of SMTK and its object‐oriented implementation. As a practical illustration, it also shows the context of use for a set of classes and discusses how the toolkit enables the user rapidly to develop, maintain and explore the full capabilities of crystallography and so create new applications. SMTK reduces the degree of effort required to construct and develop new algorithms and provides users with an easy and efficient means to test ideas, as well as to build large and maintainable models which can readily be adapted to any new situation.

Moire methods are optical neasurernent methods , that are based on the effect of superposition ofgrating lines and have been widely used in the context of industrial applications for shape analysis for non-contact measurements and for quality control of industrial components . In apf)hcations the following computations: image filtering fringe skeletonising and fringe numbering have to be performed for each test object , before comparison between the numerically reconstructed test object shape and its CAD. inodel . in oider to ieduce the computing time required by the preceeding computations , the inverse nioiré technique has been intoduced by Harthong. Instead of using a grating made of parallel straight lines , the inverse moire technique uses a pre-computed specific grating , that is formed of curved lines such that the moire pattern is composed of parallel straight fringes if the test object shape is conform to its CAD. model . Defects are then characterized by a deformation and a curvature of these parallel fringes . In this paper , we present examples showing tlia.t standard fringe extraction by automatic thresholding is not that. easy. ic) OV(ICOfl1( this (liihcultv, wc propose a four stage process a.lgorithrnical approach that. al lows fri nge det.ect.ioi i i i nverse n ot r i m ages with high sensitivity and sJ)ecificity. lirs we used the well-known image processing technique called urisharp masking , to enhaiice moire iiiage and to emphasize low contrasted fringes. The second SteJ) is to extract bright fringes by image segmentation and constrained contour modeling. After deletion of these bright fringes inside the zone of interest of the moire image, we get the thick skeleton of adjacent background and of dark fringes. The third step is to skeletonize this thick skeleton of adjacent background and of dark fringes, using morphological thinning of well-composed sets , that assures that each fringe skeleton will be one pixel thick ,at the difference of standard thinning techniques . The fourth step is to apply a graph technique to isolate the individual dark fringes. When all these four steps have been followed , one is left with a binary iniage showing the dark fringe pattern skeleton . The experimental results that have been obtained have shown the robustness of this algorithmical approach for the analysis of noisy iiiverse nioiré 111 iages 1 Introduction Moire methods are optical measurement metho(ls [2], [7] , [8] , [12], that are based oii the effect of superposition of grating lines . These techniques have 54 / SPIE Vol. 2786 0-8194-21 72-3/96/$6.00 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/21/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

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