4020155183 structure physics  probing atomic structure with neutrons, Xrays, and electrons
Digital & Präsenzbasierter Kurs
 Aims
 The aim is to acquaint students with the different methods available to probe atomic structure of inorganic and organic materials, and to equip them with handson experience in translating the theoretical tools taught during the course into computer code.
 Requirements
 Prerequisites are knowledge of undergraduate level wave optics and geometrical optics. Some experience in computer programming is helpful. However the necessary tools will also be taught during the initial exercises.
 Structure / topics / contents
 This course combines lectures on the theory of probing the structure of matter by Xrays, Neutrons, and electron with related programming Projects.
Topics discussed during the lecture will cover the following topics:
 Introduction (different ways to ‚see‘ atomic structure, origins of atomic structure)
 Fundamental scattering processes for Xrays, neutrons, and electrons
 Radiation damage & comparison between Xrays, neutrons, and electrons
 Kinematic scattering theory
 Two approaches to multiple scattering theory (Bloch wave & Multislice)
 Amorphous materials – pair distribution functions & reduced density function
 Solving crystal structures: Patterson function, direct methods, charge flipping, and Rietveld refinement
 Convergent beam electron diffraction and charge density
 Spectroscopic approaches to structure solving: Nuclear Magnetic Resonance Spectroscopy (NMR), Xray absorption/emission spectroscopy, Electron energy loss spectroscopy, Raman spectroscopy, Microwave spectroscopy
 Global numerical optimization techniques for fitting structures to data
 Tomography
Programming Projects to be developed during the course: Each participant should write an IPython Notebook document which satisfies certain criteria: It solve one of the problems below and should well document the problem and the approach used to solve it. This Project will then be presented during the exercises. Programming Projects include the following:
 Plot the interatomic forces and potentials
 Do a twoatom onedimensional MD simulation
 Measure FWHM of small angle diffraction from a 1D test function
 Fit rod width to 1D diffraction pattern
 Simulate radial SAXS profiles for spheres
 Simulate 2D Diffraction patterns of cylinders
 Load a CIFfile and compute its pairdistribution function G(r)
 Load a CIFfile and compute its partial pairdistribution function Gij(r)
 Plot Xray scattering factors for atoms and ions
 Compute structure factors of NaCl
 Compute electron structure factors of SrTiO3
 Compare Xray and electron scattering factors for atoms and ions
 Compute 2beam Pendellösung plot of SrTiO3
 Compute 2beam rocking curve of SrTiO3
 Compute 3beam 2D rocking curve of SrTiO3
 Compute the 2D projected potential of graphene in real space
 Compute the propagation of an electron wave through Carbon
 Assigned modules

P23.2.1
P23.2
P35.4
 Amount, credit points; Exam / major course assessment
 3 SWS, 5 SP/ECTS (Arbeitsanteil im Modul für diese Lehrveranstaltung, nicht verbindlich)
The final grade will be composed as follows: 50% for the programming project + 50% for the oral exam.
 Contact
 Prof. Christoph T. Koch, Raum 3'209
 Moodle link:
 http://moodle.huberlin.de/course/view.php?id=66499