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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