Chemistry 526

Introduction to X-ray Crystallography

Instructor: Dr. James Barrante

Chemistry Department

Southern CT State University

Prerequisite: CHE 371 or Department Permission

Course Description: Basic principles of X-ray diffraction and its use in the determination of the structures of crystals.

Objectives of Course: To teach students how to determine the structures of crystals using X-ray diffraction. This is a "hands on ó how to do it" course in X-ray crystallography. Students will be expected to determine the structures of actual crystals.

Modes of Instruction: lecture

Take-home projects

Course Outline:

1.    Crystal and their Properties

    (a)  Space Lattices and Unit Cells
    (b)  Planes and Indices
    (c)  Seven Crystal Systems
    (d)  Primitive and Non-primitive Systems
    (e)  Crystal Symmetry and Space Groups
    (f)  Standard Crystal Structures
2.    General Principles of Diffraction
    (a)  Light and Its Properties
    (b)  Single-slit Diffraction
    (c)  Diffraction from Parallel Slits
    (d)  Diffraction from Arrays
    (e)  Lenses and Microscopes
3.    X-rays and their Properties
    (a)  Origin of X-rays
    (b)  Absorption of X-rays
    (c)  Scattering of X-rays
    (d)  Filters
    (e)  Scattering of X-rays by Atoms
4.    Diffraction of X-rays by Crystals
    (a)  Bragg Reflection Theory
    (b)  Superposition Principle
    (c)  Structure Factors
    (d)  Fourier Synthesis
5.    The Powder Method
    (a)  Debye-Scherrer Method
    (b)  Reading a Powder Pattern
    (c)  Indexing a Powder Pattern
    (d)  Intensity Measurements and Calculations
    (e)  The Phase Problem
6.    Single Crystal Methods
    (a)  Reciprocal Lattice
    (b)  Precession Method
    (c)  Systematic Absences
    (d)  Electron Density Calculations
    (e)  Patterson Function
    (f)  Heavy Atom Method
    (g)  Direct Method
Evaluation:

There will be two examinations in the course, a midterm examination and a final examination. Each is worth 50% of the grade. The midterm examination will be an in-class written examination. The final exam, on the other hand, will consist of two parts: a practical take-home portion which will be turned in on the night of the final exam, and a written portion, which will be given in class during final exam week. The take-home portion will consist of the determination of structures of two unknown crystalline materials from data supplied by the instructor. Students will have approximately 1 month to work on the take-home portion of the final.
 
 

Bibliography:

1.    Cullity, B. D., Elements of X-ray Diffraction, 2nd ed., Addison-Wesley, Inc., Reading, MA, 1978.
2.    David, W.I.F., Shankland, K., McCusker, L.B., and Baerlocher, Ch., Structure Determination from Powder Diffraction Data, Oxford Science Publications,
       Oxford University Press, 2002.
3.    Glusker, Jenny P., and Trueblood, Kenneth N., Crystal Structure Analysis, 2nd ed., Oxford University Press, 1985.
4.    Ladd, M.F.C., and Palmer, R.A., Structure Determination by X-ray Crystallography, 2nd ed., Plenium, New York, NY, 1985.