TY - CONF A1 - Radtke, Martin T1 - Materialforschung an der BAMline T2 - Seminar Strahlenphysikalische Anwendungen in Technik und Medizin CY - Vienna, Austria DA - 2009-01-28 PY - 2009 AN - OPUS4-19183 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Constantinescu, B. A1 - Bugoi, R. A1 - Cojocaru, V. A1 - Calligaro, Th. A1 - Salomon, J. A1 - Pichon, L. A1 - Roehrs, St. A1 - Ceccato, D. T1 - Micro-SR-XRF and Micro-PIXE studies for archaeological gold identification - The case of Carpathian (Transylvanian) gold and of Dacian bracelets T2 - Ecaart 9 CY - Florence, Italy DA - 2007-09-03 PY - 2007 AN - OPUS4-17862 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reiche, I. A1 - Berger, Achim A1 - Duval, A. A1 - Guicharnaud, H. A1 - Merchel, Silke A1 - Radtke, Martin A1 - Schäfer, D. A1 - Simon, R. T1 - SY-XRF study of silverpoint drawings of Hans Baldung Grien from the Karlsruher Skizzenbuch and the corresponding silver stylus (16th c.) T2 - European Conference on X-Ray Spectrometry CY - Paris, France DA - 2006-06-19 PY - 2006 AN - OPUS4-16279 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simons, C. A1 - Mans, C. A1 - Hanning, S. A1 - Janßen, A. A1 - Alber, D. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Kreyenschmidt, M. T1 - New polymeric reference materials for XRF and LA-ICP-MS - development and characterization T2 - POLYDAYS 2008, Active and Adaptive Polymeric Materials, Freie Universität Berlin CY - Berlin, Germany DA - 2008-10-01 PY - 2008 AN - OPUS4-17832 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simons, C. A1 - Mans, C. A1 - Hanning, S. A1 - Janßen, A. A1 - Kreyenschmidt, M. A1 - Alber, D. A1 - Radtke, Martin A1 - Reinholz, Uwe T1 - New polymeric reference materials for XRF and LA-ICP-MS - development and characterization T2 - European Conference on X-ray Spectrometry CY - Dubrovnik, Croatia DA - 2008-06-16 PY - 2008 AN - OPUS4-17844 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simons, C. A1 - Mans, C. A1 - Hannig, S. A1 - Alber, D. A1 - Radtke, Martin A1 - Reinholz, Uwe T1 - New polymeric reference materials for XRF and LA-ICP-MS - development and characterization T2 - BESSY Users' Meeting 2008 CY - Berlin, Germany DA - 2008-12-04 PY - 2008 AN - OPUS4-18223 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reiche, I. A1 - Berger, Achim A1 - Görner, Wolf A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Duval, A. A1 - Guicharnaud, H. A1 - Riederer, J. T1 - Auf den Spuren Albrecht Dürers - Zertörungsfreie Untersuchung von Silberstiftzeichnungen mittels micro-PIXE und Synchrotron-induzierte micro-RFA T2 - Jahrestagung des Arbeitskreises Archäometrie in der Fachgruppe Analytische Chemie der Gesellschaft Deutscher Chemiker (GDCh) CY - Berlin, Germany DA - 2003-03-12 PY - 2003 AN - OPUS4-3795 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reiche, I. A1 - Berger, Achim A1 - Görner, Wolf A1 - Guicharnaud, H. A1 - Merchel, Silke A1 - Radtke, Martin A1 - Riederer, J. A1 - Riesemeier, H. A1 - Roth, M. A1 - Duval, A. A1 - Bevers, H. T1 - Non-Destructive investigations of Dürer's silver point drawings by pixe and sr-xrf T2 - 7th International Conference on Non-Destructive Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, Congress Centre Elzenveld CY - Antwerp, Belgium DA - 2002-06-02 PY - 2002 AN - OPUS4-2995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merchel, Silke A1 - Berger, Achim A1 - Görner, Wolf A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Reiche, I. A1 - Riederer, J. A1 - Duval, A. A1 - Guicharnaud, H. T1 - Non- Destructive Investigations of Dürer's Silver Point Drawings by Pixe and SY-XRF T2 - 7th International Conference on Non-Destructive Testing and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, Congress Centre Elzenveld CY - Antwerp, Belgium DA - 2002-06-02 PY - 2002 AN - OPUS4-2982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Görner, Wolf A1 - Matschat, Ralf A1 - Riesemeier, Heinrich A1 - Eichelbaum, M. A1 - Rademann, K. T1 - XANES Measurements On Glass Samples at the BAMline T2 - PRORA-Fachtagung "Prozessnahe Röntgenanalytik" CY - Berlin, Germany DA - 2005-11-24 PY - 2005 AN - OPUS4-11651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Constantinescu, B. A1 - Vasilescu, A. A1 - Radtke, Martin A1 - Reinholz, Uwe T1 - A study on gold and copper provenance for romanian prehistoric objects using Micro-SR-XRF T2 - Synchrotron Radiation in Art & Archaeology CY - Amsterdam, Netherlands DA - 2010-11-07 PY - 2010 AN - OPUS4-21324 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Grunewald, Andreas A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe T1 - SRXRF - measurements at non planar objects: Automatic determination of the angle of inicidence of the exciting X-ray T2 - Synchroton Radiation in Art & Avhaelogy (SR2A-2010) CY - Amsterdam, Netherlands DA - 2010-11-07 PY - 2010 AN - OPUS4-21378 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Constantinescu, B. A1 - Radtke, Martin A1 - Bugoi, R. A1 - Vasilescu, A. A1 - Calligaro, Th. A1 - Salomon, J. A1 - Pichon, L. A1 - Röhrs, S. A1 - Ceccato, D. A1 - Pop, D. T1 - Archaeological gold provenance studies based on SR-XRF and micro-PIXE analyses T2 - 20th General Meeting of the International Mineralogical Association (IMA2010) CY - Budapest, Hungary DA - 2010-08-21 PY - 2010 AN - OPUS4-22025 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Christea-Stan, D. A1 - Constantinescu, B. A1 - Vasilescu, A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Popescu, Gh. A1 - Neacsu, A. A1 - Ceccato, D. T1 - Micro-SR-XRF and micro-PIXE studies for archaeological gold identification - the case of Transylvanian gold T2 - 20th General Meeting of the International Mineralogical Association (IMA2010) CY - Budapest, Hungary DA - 2010-08-21 PY - 2010 AN - OPUS4-22026 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zier, M. A1 - Munnik, F. A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Radtke, Martin T1 - Accurate stopping power determination of 15N ions hydrogen depth profiling by a unique combination of ion beams and synchrotron radiation T2 - 20th International Conference on Ion Beam Analysis CY - Itapema, Brazil DA - 2011-04-10 PY - 2011 AN - OPUS4-23607 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Scharf, O. A1 - Wedell, R. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Langhoff, N. A1 - Soltau, H. A1 - Ihle, S. T1 - X-ray color camera, a detector with high resolution in energy and space T2 - E-MRS 2011 SPRING MEETING CY - Nice, France DA - 2011-05-09 PY - 2011 AN - OPUS4-23267 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Constantinescu, B. A1 - Vasilescu, A. A1 - Radtke, Martin A1 - Reinholz, Uwe T1 - XRF and micro-SR-XRF studies for Dacian gold jewelry authentication T2 - European Conference on X-Ray Spectrometry CY - Figueira da Foz, Portugal DA - 2010-06-20 PY - 2010 AN - OPUS4-23737 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabral, A.R. A1 - Lehmann, B. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Kwitko-Ribeiro, R. A1 - Tupinambá, M. T1 - Iodine fingerprints biogenic fixation of platinum and palladium T2 - Goldschmidt 2011 CY - Prague, Czech Republic DA - 2011-08-14 PY - 2011 AN - OPUS4-23606 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Buzanich, Günter A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich T1 - X-ray Fluorescence analysis using synchrotron radiation excitation T2 - 75. Jahrestagung der DPG und DPG Frühjahrstagung CY - Dresden, Germany DA - 2011-03-13 PY - 2011 AN - OPUS4-24023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Understanding and Machine Learning of Materials Properties with Quantum-Chemical Bonding Analysis N2 - Bonds and local atomic environments are crucial descriptors for material properties. They have been used to create design rules for materials and are used as features in machine learning of material properties. This talk will show how our recently developed tools, that automatically perform quantum chemical bond analysis and enable the study of chemical bonds and local atomic environments, accelerate and improve the development of such heuristics and machine-learned models for materials properties. T2 - Accelerate Conference 2023 CY - Toronto, Canada DA - 22.08.2023 KW - Automation KW - DFT KW - Bonds PY - 2023 AN - OPUS4-58131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strub, Erik A1 - Riesemeier, Heinrich A1 - Radtke, Martin T1 - SRXRF zur Zertifizierung von Referenzmaterialien T2 - SAAGAS 21 - Seminar Aktivierungsanalyse und Gammaspektroskopie CY - Mainz, Germany DA - 2007-03-21 PY - 2007 AN - OPUS4-14669 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Data-driven chemical understanding with geometrical and quantum-chemical bonding analysis N2 - Chemical bonding and coordination environments are crucial descriptors of material properties. They have previously been applied to creating chemical design guidelines and chemical heuristics. They are currently being used as features in machine learning more and more frequently. I will discuss implementations and algorithms (ChemEnv and LobsterEnv) for identifying these coordination environments based on geometrical characteristics and chemical bond quantum chemical analysis. I'll demonstrate how these techniques helped in testing chemical heuristics like the Pauling rule and thereby improved our understanding of chemistry. I'll also show how these tools can be used to create new design guidelines and a new understanding of chemistry. To use quantum-chemical bonding analysis on a large-scale and for machine-learning approaches, fully automatic workflows and analysis tools have been developed. After presenting the capabilities of these tools, I will also point out how these developments relate to the general trend towards automation in the field of density functional based materials science. T2 - ICAMS Interdisciplinary Centre for Advanced Materials Simulation Seminar Series CY - Online meeting DA - 24.11.2022 KW - Automation KW - High-throughput KW - Machine learning KW - Materials informatics KW - Bonding Analysis PY - 2022 AN - OPUS4-56417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - New chemical understanding with the help of automation and highthroughput computations N2 - High-throughput computations are nowadays an established way to suggest new candidate materials for applications to experimentalists. Due to new packages for automation and access to databases of computed materials properties, these studies became more and more complex over the last years. Besides suggesting new candidate materials for applications, they also offer a way to understanding the materials properties based on chemical bonds. For example, we have recently used orbital-based bonding analysis to understand the results of high-throughput studies for spintronic materials, ferroelectric materials and photovoltaic materials in detail. To do so, we have developed Python tools for high-throughput bonding analysis with the programs VASP and Lobster (see www.cohp.de). They are based on the Python packages pymatgen, atomate, and custodian. This implementation will be discussed within the talk. We also expect that these tools offer possibilities to arrive at new descriptors based on chemical bonds for materials properties. T2 - High-throughput workflows for materials science with the Atomic Simulation Environment (ASE) and Fireworks CY - Lyngby, Denmark DA - 15. November 2021 KW - Automation KW - High-throughput computations KW - DFT PY - 2021 AN - OPUS4-53840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rakotondrajoa, Andrianiaina A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Raboanary, R. A1 - Vincze, L. T1 - Determination of the Efficiency of a Silicon Drift Detector (SDD9 by Monte Carlo Simulation T2 - Denver X Ray Conferences 2012 CY - Denver, CO, USA DA - 2012-08-06 PY - 2012 AN - OPUS4-27185 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinholz, Uwe A1 - Munnik, F. A1 - Michalak, P. P. A1 - Radtke, Martin A1 - Buzanich, Günter A1 - Merchel, S. A1 - Renno, A. D. A1 - Riesemeier, Heinrich T1 - Spatially-resolved analysis of natural minerals as carriers of high-tech metals and Rare Earth Elements: comparison of EPMA, PIXE and Sy-µXRF T2 - 13th INTERNATIONAL CONFERENCE ON NUCLEAR MICROPROBE TECHNOLOGY & APPLICATIONS 2012 CY - Lisbon, Portugal DA - 2012-07-22 PY - 2012 AN - OPUS4-26962 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rakotondrajoa, Andrianiaina A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Raboanary, R. A1 - Vincze, L. T1 - Improvement of PLS regression based XRF spectroscopy quantification using multiple step procedure and Monte Carlo simulation T2 - 12th International Symposium on Radiation Physics CY - Rio de Janeiro, Brazil DA - 2012-10-07 PY - 2012 AN - OPUS4-27186 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - First experiences with the combination of polycapillary optics and an energy dispersive pn- CCD detector at BAMline at Bessy T2 - X-ray micro-fluorescence spectroscopy at the PETRA III extension: second user workshop CY - Hamburg, Germany DA - 2011-09-27 PY - 2011 AN - OPUS4-26924 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Bjeoumikhov, S. A1 - Ihle, S. A1 - Soltau, H. A1 - Langhoff, N. A1 - Wedell, R. T1 - The Colour X-ray Camera: Basics, Applications and Perspectives T2 - 11th International Conference on Synchrotron Radiation Instrumentation CY - Lyon, France DA - 2012-07-09 PY - 2012 AN - OPUS4-27184 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Röntgenfluoreszenzanalyse mit Synchrotronstrahlung an der Bundesanstalt für Materialforschung und -prüfung (BAM), Berlin T2 - Seminar: "Strahlenphysikalische Anwendungen in Technik und Medizin" CY - Vienna, Austria DA - 2011-11-23 PY - 2011 AN - OPUS4-26926 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - The colour Xray camera: basics, applications and perspectives T2 - Analytik 2012 CY - Beijing, China DA - 2012-03-23 PY - 2012 AN - OPUS4-26922 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - The colour Xray camera: basics, application and perspectives T2 - EXRS 2012 CY - Vienna, Austria DA - 2012-06-18 PY - 2012 AN - OPUS4-26925 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Die Himmelsscheibe von Nebra: Vermutungen und Fakten T2 - Schul- und Volkssternwarte CY - Dahlewitz, Germany DA - 2012-03-09 PY - 2012 AN - OPUS4-26927 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Praktische Anwendung der Atomtheorie T2 - Galileo Gymnasium CY - Berlin, Germany DA - 2012-08-30 PY - 2012 AN - OPUS4-26923 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Buzanich, Günter A1 - Michalak, P. P. A1 - Renno, A. D. A1 - Merchel, S. A1 - Munnik, F. T1 - Homogeneity testing of natural candidate reference materials for resource technology by three spatially-resolved X-ray methods T2 - ANAKON CY - Essen, Germany DA - 2013-03-04 PY - 2013 AN - OPUS4-27868 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Hahn, M. T1 - Investigation of the bone tissue contamination with implatcomponents after metal-on-metal hip resurfacing arthrolasty. T2 - 4th joint BER II and BESSY II user meeting 2012 CY - Berlin, Germany DA - 2012-12-12 PY - 2012 AN - OPUS4-27253 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lingott, Jana A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Gadolinium-basierte MRT, Kontrastmittel in biologischen Proben T2 - 46. Jahrestagung der Deutschen Gesellschaft für Massenspektrometrie CY - Berlin, Germany DA - 2013-03-10 PY - 2013 AN - OPUS4-28033 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Hahn, M. T1 - Tissue contamination with implant components after metal-on-metal hip resurfacting arthoplasty T2 - European Conference on X-Ray Spectrometry (EXRS) CY - Vienna, Austria DA - 2012-06-18 PY - 2012 AN - OPUS4-27191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lingott, Jana A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Gadolinium-basierte MRT, Kontrastmittel in biologischen Proben T2 - CANAS 2013 - Colloquium Analytische Atomspektroskopie CY - Freiberg, Germany DA - 2013-03-17 PY - 2013 AN - OPUS4-28034 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Rakotondrajoa, Andrianiaina A1 - Raboanary, R. T1 - New approach for PLS regression based XRF spectroscopy quantification method T2 - European Conference on X-Ray Spectrometry (EXRS) CY - Vienna, Austria DA - 2012-06-18 PY - 2012 AN - OPUS4-27188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Wenzel, Klaus-Jürgen A1 - Biermann, Jirka A1 - Hollesch, Martin A1 - Gubzhokov, R. A1 - Reinholz, Uwe T1 - WDX - ein wellenlängendispersives Spektrometer für die BAMline T2 - Lange Nacht der Wissenschaften 2013 CY - Berlin, Germany DA - 2013-06-08 PY - 2013 AN - OPUS4-28622 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine A1 - Naik, Aakash Ashok A1 - Ertural, Christina A1 - Dhamrait, Nidal A1 - Benner, Philipp T1 - A Quantum-Chemical Bonding Database for Solid-State Materials N2 - A deep insight into the chemistry and nature of individual chemical bonds is essential for understanding materials. Bonding analysis is expected to provide important features for large-scale data analysis and machine learning of material properties. Such information on chemical bonds can be calculated using the LOBSTER (www.cohp.de) software package, which post-processes data from modern density functional theory computations by projecting plane wave-based wave functions onto a local atomic orbital basis. We have performed bonding analysis on 1520 compounds (insulators and semiconductors) using a fully automated workflow combining the VASP and LOBSTER software packages. We then automatically evaluated the data with LobsterPy (https://github.com/jageo/lobsterpy) and provide results as a database. The projected densities of states and bonding indicators are benchmarked on VASP projections and available heuristics, respectively. Lastly, we illustrate the predictive power of bonding descriptors by constructing a machine-learning model for phononic properties, which shows an increase in prediction accuracies by 27 % (mean absolute errors) compared to a benchmark model differing only by not relying on any quantum-chemical bonding features. T2 - Sommersymposium des Fördervereins Chemieolympiade CY - Online meeting DA - 15.04.2023 KW - Automation KW - Chemical Bonds KW - DFT KW - Quantum Chemistry PY - 2023 AN - OPUS4-57310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Data-driven chemical understanding with geometrical and quantum-chemical bonding analysis N2 - Chemical bonding and coordination environments are crucial descriptors of material properties. They have previously been applied to creating chemical design guidelines and chemical heuristics. They are currently being used as features in machine learning more and more frequently. I will discuss implementations and algorithms (ChemEnv and LobsterEnv) for identifying these coordination environments based on geometrical characteristics and chemical bond quantum chemical analysis. I will demonstrate how these techniques helped in testing chemical heuristics like the Pauling rule and thereby improved our understanding of chemistry. I will also show how these tools can be used to create new design guidelines and a new understanding of chemistry. To use quantum-chemical bonding analysis on a large-scale and for machine-learning approaches, fully automatic workflows and analysis tools have been developed. After presenting the capabilities of these tools, I will also point out how these developments relate to the general trend towards automation in the field of density functional based materials science. T2 - UniSysCat - Colloquium CY - Berlin, Germany DA - 08.02.2023 KW - Automation KW - Chemical Bonds KW - High-throughput KW - Data Analysis PY - 2023 UR - https://www.unisyscat.de/news-events/display?tx_news_pi1%5Baction%5D=detail&tx_news_pi1%5Bcontroller%5D=News&tx_news_pi1%5Bnews%5D=386&cHash=f95c8af783c08c2c6039440145a036bb AN - OPUS4-57051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertural, Christina A1 - George, Janine T1 - Vibe Check via Machine Learning: Testing the Prototype N2 - Vibrational properties play a key role in determining the stability and thermal conductivity behaviour of materials. The quasi- harmonic approximation gives insight into the phononic properties of a compound, but in the established way, i.e. density functional theory based methods, it takes many calculation steps and consumes a lot of resources to arrive at the desired results. Machine learning (ML) trained interatomic potentials (e.g. Gaussian approximation potential, GAP) pose an alternative to the traditional computation way of phonons. We develop a Python code based workflow which combines automation tools like atomate2 with ML to ease providing interactomic potentials for (quantum chemical) computations and databases. T2 - #RSCPoster Twitter conference 2023 CY - Online meeting DA - 28.02.2023 KW - Interatomic potentials KW - Machine learning KW - Phonons KW - Workflow PY - 2023 UR - https://twitter.com/cer5814012/status/1630547004462858240 AN - OPUS4-57059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bustamante, Joana A1 - Naik, Aakash Ashok A1 - Ertural, Christina A1 - Ueltzen, Katharina A1 - George, Janine T1 - Thermodynamic and Thermoelectric Properties of the Canfieldite, (Ag8SnS6 ), in the Quasi-Harmonic Approximation N2 - Argyrodite-type materials have lately sparked a lot of research interest due to their thermoelectric properties.One promising candidate is canfieldite (Ag8SnS6), which has a Pna21 orthorhombic crystal structure at room temperature (RT). Recently, a new low-temperature (LT) phase transition of canfieldite at 120K has been found. Here, we investigate structural, vibrational and thermodynamic properties of Ag8SnS6 at room- and low-temperature employing density functional theory (DFT) and lattice dynamics computations. Thermal properties calculations were based on the quasi-harmonic approximation (QHA) as implemented in phonopy. We achieve good agreement with experiments. Thermal properties such as the constant-pressure heat capacity (Cp) and thermal conductivity are very close to experimental measurements. Furthermore, we compared RT and LT Ag8SnS6 Grüneisen parameters with argyrodites analogues, Ag8XS6 (X = Sn, Si, Ge), to arrive at an improved T2 - 16th International conference on materials chemistry (MC16) CY - Dublin, Ireland DA - 03.07.2023 KW - Thermoelectric materials KW - DFT KW - QHA KW - Grüneisen parameter PY - 2023 AN - OPUS4-57887 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Data-driven chemical understanding and machine learning of materials properties N2 - Bonds and local atomic environments are crucial descriptors of material properties. They have been used to create design rules and heuristics for materials. More and more frequently, they are used as features in machine learning. Implementations and algorithms (e.g., ChemEnv and LobsterEnv) for identifying these local atomic environments based on geometrical characteristics and quantum-chemical bonding analysis are nowadays available. Fully automatic workflows and analysis tools have been developed to use quantum-chemical bonding analysis on a large scale and for machine-learning approaches. The latter relates to a general trend toward automation in density functional-based materials science. The lecture will demonstrate how our tools, that assess local atomic environments, helped to test and develop heuristics and design rules and an intuitive understanding of materials. T2 - 16th International conference on materials chemistry (MC16) CY - Dublin, Irland DA - 03.07.2023 KW - Automation KW - Bonding Analysis KW - Materials Informatics PY - 2023 AN - OPUS4-57876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Automation and Workflows in Computational Materials Science N2 - This talks describes why we need automation and workflows in materials informatics. It introduces tools to automatize tasks in computational materials science. Furthermore, a bonding analysis and a phonon workflow are presented. T2 - Seminar in Theoretical Chemistry Group atFU Berlin CY - Berlin, Germany DA - 06.12.2022 KW - Automation KW - Workflows KW - Density functional theory PY - 2022 AN - OPUS4-56524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertural, Christina A1 - Deringer, V. A1 - George, Janine T1 - Automation of machine learning driven interatomic potential generation for predicting vibrational properties N2 - Knowing phonon properties is beneficial for predicting low thermal conductivity thermoelectric materials. Employing DFT consumes lots of computational resources. Using ML-driven interatomic potentials (MLIP, e.g., GAP) opens up a faster route, but most potentials are specifically tailored to a certain compound. We aim to generalize the MLIP generation in a Python code-based workflow, combining automatic DFT runs with automated GAP fits. Automation enables easier tests, benchmarks, and validation. T2 - SALSA Make and Measure Conference: Interfaces CY - Berlin, Germany DA - 13.09.2023 KW - Interatomic potentials KW - Machine learning KW - Phonons KW - Thermoelectrics KW - Automated workflows PY - 2023 AN - OPUS4-58374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash Ashok A1 - Ertural, Christina A1 - Dhamrait, Nidal A1 - Benner, Phillip A1 - George, Janine T1 - A Quantum-Chemical Bonding Database for Solid-State Materials N2 - Understanding the chemistry and nature of individual chemical bonds is essential for materials design. Bonding analysis via the LOBSTER software package has provided valuable insights into the properties of materials for thermoelectric and catalysis applications. Thus, the data generated from bonding analysis becomes an invaluable asset that could be utilized as features in large-scale data analysis and machine learning of material properties. However, no systematic studies exist that conducted high-throughput materials simulations to curate and validate bonding data obtained from LOBSTER. Here we present an approach to constructing such a large database consisting of quantum-chemical bonding information. T2 - 16th International conference on materials chemistry (MC16) CY - Dublin, Ireland DA - 03.07.2023 KW - Bonding analysis KW - Automation KW - Materials Informatics KW - Computational Chemistry KW - Database PY - 2023 AN - OPUS4-57889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cakir, Cafer Tufan A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Streli, Christina A1 - Radtke, Martin T1 - Scanning-Free Grazing Exit XANES Analysis of Stratified Samples and the Optimization of the Data Collection Process N2 - The components that are used in structural and in high temperature applications generally face significant challenges with respect to oxidation behaviours and metalworking processes. In most of the cases, harsh environmental conditions lead materials to degrade due to corrosion. To thoroughly investigate the corrosion processes and to determine oxidation states of metal components within the reaction products, we need special analytical tools. Grazing exit X-ray fluorescence (GEXRF) offers a non-destructive way to collect this information in sub-micrometre depth range. In order to obtain structural information, such as regarding oxidation states or atomic/molecular geometric arrangement, the GEXRF approach can also be combined with the X-ray absorption spectroscopy (XAS) method. The position and energy sensitive detector, with 264x264 pixel detector area, provides information regarding the signal emitted from the sample as a function of the emission angle and thus allows depth-sensitive analysis. Furthermore, the data collected from samples of an incidence energy which can be controlled with a resolution of 0.5 eV provides XANES data to determine oxidation states. We address the feasibility of our setup and provide a new optimization procedure (Bayesian Optimization and Gaussian Regression) to decrease measuring time. The results settle on a conceptual study on a reference sample (Cr-Oxide layer (300nm) on Cr layer (500nm) on Si wafer). T2 - Denver X-Ray Conference DXC 2022 CY - Washington D.C., USA DA - 07.08.2022 KW - GEXRF KW - High entropy alloys KW - High entropy materials KW - Optimization KW - XANES KW - Grazing exit KW - XAS PY - 2022 AN - OPUS4-56271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cakir, Cafer Tufan A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Streli, Christina A1 - Radtke, Martin T1 - High Speed for High Entropy Materials N2 - Time is the most valuable parameter in synchrotron experiments. This is costly and some of the experiments suffer from low efficiency due to low counting statistics. With today's high processing power long experiments are run in a shorter time and increase efficiency. With optimization algorithms time in "counting-hungry" experiments reduced by factor of 10. Our project is to develop a new method to analyze the chemical properties of complex materials non-destructively and efficiently, such as high entropy materials subjected to corrosion processes. A better understanding of the corrosion process will help to develop corrosion-resistant materials and reduce the cost of corrosion damage, which averages around 2.5 trillion USD annually. T2 - Berlin Science Week CY - Berlin, Germany DA - 01.11.2022 KW - GEXRF KW - High entropy alloys KW - XANES KW - High entropy materials KW - Grazing exit KW - XAS KW - Optimization PY - 2022 AN - OPUS4-56269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -