CHEM 712/7120 - X-Ray Diffraction

Semester: Fall 2021

Professor: J. Assoud | Discipline: Inorganic | Campus: Waterloo

Description

This course will examine, in detail, the theory and the practice of the x-ray structure determination.

We will review the definition of the crystal structure, unit cell, crystal systems, Bravais lattices and describe the crystal structure of some elements (BCC, CCP, HCP…), binary (e.g. NaCl…), and ternary (CaTiO3 …) and other solids (Ba2YCu3O7-x …).

We will introduce the notion of symmetry operations and their symmetry elements (e.g. inversion centre, rotation axis, rotoinversion axis …), and point groups followed by the infinite symmetry elements (screw axis, glide plane).

We will discuss the space groups and their symbols and projections, the use of the International Tables, Wyckoff positions and some examples of crystal structures.

We will develop the theory of the x-ray diffraction on single crystal and powder material, by introducing the Bragg’s law, Miller indices, reciprocal lattice, Ewald sphere, Laue group, structure factor, systematic absences, peak intensity, peak position, peak shape, Rietveld refinement on powder sample, etc.

After learning about the strategy of the data collection and reduction, we will solve the phase problem using the Patterson, heavy atom and direct method and we will finish with the structure refinement, which is illustrated with examples from all synthetic disciplines (inorganic, organometallic and organic) using Shelx-program.

The last chapter will explore the different techniques used for the growth of single crystal suitable for single crystal x-ray diffraction and the notion of twining in crystallography.

During the class, we will visit the x-ray laboratory (depending on the COVID regulations) and use some crystals provided by the students for the demonstration of full structure determination.

Please expect some changes due to the COVID

Materials

– G. H. Stout, L. H. Jensen, X-ray Structure Determination, A Practical Guide, Second Edition Wiley.

– W. Massa, Crystal Structure Determination, Springer.

– V. K. Pecharsky, P. Y. Zavalij, Fundamentals of powder diffraction and structural characterization of materials, Springer.

– M O.Keeffe & B.G. Hyde, Pattern and Symmetry

– M. F. C. Ladd & R.A. Palmer, Structure Determination by X-ray Crystallography.

– Dennis. W. Bennet, Understanding Single-Crystal X-ray Crystallography, Wiley.

– C. Giacovazzo, H. L. Monaco, G. Artioli, D. Viterbo, M. Milanesio, G. Ferraris, G. Gilli, P. Gilli, G. Zanotti, M. Catti, Fundamentals of Crystallography, Third edition, IUCR, Oxford university press.

– International tables for Crystallography: Bilbao Server: http://www.cryst.ehu.es/

Evaluation

1- Homework (assignments, presentation or paper report): 50%

2- Midterm:                                                                25%

3- Final:                                                                      25%

Lab/Project

TBA

Schedule

  • Tue: 7:00 pm - 9:20 pm in EIT 2053/MacN 101

Office Hours

Monday and Thursday 1:00: 2:00pm E-mail: [email protected]