《高级化学实验与仪器》麻省理工学院化学系讲义!

麻省理工学院课件----Physical Methods in Inorganic Chemistry, Spring 2005

Physical Methods in Inorganic Chemistry, Spring 2005
Molecular model of the amino acid tyrosine with experimental electron density in front of an X-ray diffractometer at MIT. The tyrosine is part of the crystal structure of phosphoglycerate mutase from M. tuberculosis. See P. Mueller et al. (2005). Acta Cryst. D61, 309-315. (Figure and photograph by Dr. Peter Mueller. Used with permission.)

课程特点Highlights of this Course

This course features a selection of downloadable 讲义.
课程简介Course Description

This course covers the following topics: X-ray diffraction: symmetry, space groups, geometry of diffraction, structure factors, phase problem, direct methods, Patterson methods, electron density maps, structure refinement, how to grow good crystals, powder methods, limits of X-ray diffraction methods, and structure data bases.

Staff
Instructor:
Dr. Peter Mueller
Course Meeting Times
Lectures:
Eighteen sessions for 7 weeks
1 hour / session
Level
Graduate
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Introduction (PDF)
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Overview, Textbooks, History of Crystallography
2 Symmetry in 2D (PDF)
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Definition of Symmetry, Introduction of Symmetry Operators

Compatibility of Symmetry Operators with Translation

Combining Symmetry Operations and Determination of Plane Groups
3 Symmetry in 3D (PDF - 1.0 MB)
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Extension of the Plane Groups Concept to the Third Dimension: Space Groups

Introduction of Screw Axes and Glide Planes

Point Groups v/s Space Groups

The Unit Cell and Crystallographic Conventions
4 X-rays and Matter (PDF)
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X-ray Generation

Diffraction Experiment with Optical Grids and Laser Pointers

Convolution Theorem and Fourier Transformation

Introduction of Bragg's Law and Miller Indices
5 Geometry of Diffraction (PDF)
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Reciprocal Space v/s Real Space

Ewald Construction as a Geometric Interpretation of Bragg's Law
6 Structure Factors

Real Atoms are no Point Atoms (Atomic Form Factors) and Show Thermal Motion (Atomic Displacement Factors)

Having More than One Atom per Unit Cell Leads to Structure Factors

Fourier Transformation Gives Rise to Electron Density; Crystallographic Resolution
7 Structure Factors II (PDF - 1.8 MB)
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Complex Numbers, Euler's Equation and the Argand Plane

Introduction of the Phase Problem
8 Symmetry in Reciprocal Space (PDF)
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Introduction of Friedel's Law and Laue Groups

Space Group Determination: |E2-1| Statistics, Systematic Absences, Crystallographic Directions for Triclinic, Monoclinic, Orthorhombic and Tetragonal Systems

Introduction of the Patterson Function and Harker Sections, as well as Direct Methods for Structure Solution
9 Structure Refinement (PDF)
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Different Types of Electron Density Maps (Fo, Fc, Fo-Fc, etc.)

Introduction of Anisotropic Displacement Parameters

Minimization Functions: The Least-squares Approach and Different R-factors

Crystallographic Parameters, Constraints and Restraints
10 Structure Refinement II

Problems and Pitfalls: Wrong Space Group, Atom Type Assignment (All Electrons are Blue), Disorder, Twinning

What are Artifacts (Libration, C-C Triple Bonds, Fourier Truncation Ripples, etc.)?

Finding the Hydrogen Atoms, "Riding Model"
11 Anomalous Scattering (PDF)
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Absorption of X-ray Photons Leads to Loss of Symmetry in Orbital Geometry, Which Results in a Violation of Fridel's Law
12 Practical Aspects and Related Methods

Growing Crystals and Keeping Them Alive (Never Remove the Mother Liquor!)

Mounting Crystals onto the Diffractometer

Short Introduction of Powder Diffraction, Neutron Diffraction and EXAFS

Crystallographic Data Bases (ICSD, CSD, PDB, Reciprocal Net)
13 Quick Recap

Symmetry, Bragg's Law, Miller Indices, Real Space v/s Reciprocal Space, Ewald Construction, Structure Factors, Electron Density, Symmetry in Reciprocal Space, Laue Groups v/s Point Groups v/s Space Groups, Space Group Determination, Patterson Function, Structure Refinement, Parameters / Constraints / Restraints, Anisotropic Displacement Parameters, Libration, Hydrogen Atoms
14 Exam

You have 50 minutes to answer all questions. You can use pens, a calculator, ruler and compass, as well as a letter sized piece of paper with anything written on it. No books or other material is allowed.

不错的东西！

非常好,谢谢!