Titel:
„Rietveld refinement of the crystal structure of sodium-para-hydroxybenzoate using the GSAS program system: a practical guide“
R.E. Dinnebier (Herausgeber – editor)
Inhalt – Table of contents:
| 1. | Introduction to the crystallographic problem | |
| 2. | Powder X-ray diffraction experiments | |
| 3. | Program files needed | |
| 3.1 | The GSAS program system | |
| 3.2 | The VRML viewer program | |
| 3.3 | The MATHCAD explorer | |
| 4. | Input files needed | |
| 4.1 | NABENZO.GDA: Measured intensities | |
| 4.2 | NABENZO.BG: Manual background | |
| 4.3 | X3B1.PAR: Instrument parameter file | |
| 4.4 | NABENZO.ATO: List of atoms | |
| 4.5 | NABENZO.MCD: Mathcad file | |
| 4.6 | NABENZO.EXP: Experiment data file | |
| 5. | General principles of GSAS | |
| 6. | The Lebail fit | |
| 6.1 | Preparing a new experiment file in GSAS | |
| 6.2 | Run powder data preparation | |
| 6.3 | Run general least squares | |
| 6.4 | Refining additional profile parameters | |
| 6.5 | Refining the zero shift | |
| 6.6 | Plotting of the refined powder diffraction data | |
| 6.7 | Wavelength shift | |
| 6.8 | Anisotropic peak broadening due to micro strain | |
| 6.9 | Extracting intensities for crystal structure determination | |
| 7. | The Rietveld fit | |
| 7.1 | Refining the scale factor only | |
| 7.2 | Introducing additional atoms | |
| 7.3 | Fixing the floating origin | |
| 7.4 | What to do in case of divergence of the refinement | |
| 7.5 | How to use rigid bodies with satellite groups in GSAS | |
| 7.6 | How to perform a difference Fourier analysis | |
| 7.7 | Refining the position of the missing hydroxy-hydrogen atom | |
| 7.8 | Calculate the R-F and R-F2 values of the refinement | |
| 7.9 | Switching the soft constraints | |
| 8. | Description of the structure of Na-para-hydroxybenzoate | |
| 8.1 | Calculate the bond lengths and angles of the refined structure | |
| 8.2 | Results and discussion of the crystal structure of Na-para-hydroxybenzoate | |
| 8.3 | Visualization of the anisotropic strain tensor | |
| 9. | References |