Prof. Dr. Richard DronskowskiChair of Solidstate and Quantum Chemistry
Chair of SolidState and Quantum ChemistryWelcome to the Chair of SolidState and Quantum Chemistry at RWTH Aachen University, Europe's largest Technical University dating back to the year 1870. The following pages are intended to offer you a short overview of our research and teaching activities in the fields of solidstate and quantum chemistry. If you are interested in these exciting chemical disciplines, you have come to the right place. Stay with us! Don't go away! HOT: The LOBSTER chemicalbonding computer programThe computer program LOBSTER (Local Orbital Basis Suite Towards ElectronicStructure Reconstruction) enables chemicalbonding analysis based on periodic planewave (PAW) densityfunctional theory output and is applicable to a wide range of firstprinciples simulations in solidstate and materials chemistry. LOBSTER incorporates analytic projection routines described previously and offers improved functionality. It calculates, among others, atomprojected densities of states, projected crystal orbital Hamilton population curves, and the recently introduced bondweighted distribution function. The software is offered freeofcharge for noncommercial research. HOT: Twodimensional Rietveld refinement of POWGEN dataThe method of angular and wavelengthdispersive (= 2D) Rietveld refinement is an emerging tool for the analysis of neutron diffraction data measured at TOF instruments with large area detectors. We elaborate on the necessary steps to perform such technique using the POWGEN instrument as an example. A dataset measured on a standard diamond sample is used to extract the profile function, and the variation of reflection width with 2θ and λ can be expressed by the standard equation for the instrumental resolution, which yields a substantially more fundamental approach to the peak shape. Geometrical considerations of the POWGEN instrument and sample effects lead to values for Δθ, Δt and ΔL that yield a very good match to the extracted FWHM values and allow for the final 2D Rietveld refinement.
