Get-together party                                                                                                                                                       

General introduction to the programs of the FULLPROF Suite.
Web site: downloading the suite and individual programs.
The use of the FPS_Toolbar for accessing the programs.
Consulting the manuals and documentation.
Utilities: crystallographic calculator, symmetry, powder pattern calculations, visualisation of reciprocal space for single crystals, etc.

Use of the program WINPLOTR for visualising diffraction patterns, peak detection and peak fit, exporting background, visualisation of 3D plots, 2D detectors, etc.

Indexing powder diffraction patterns (with the indexing programs: DICVOL04, TREOR-90, etc).

Determination of propagation vectors of superstructures and incommensurate magnetic structures. Program: k_Search.

Format of diffraction pattern files, superposition of diffraction patterns using a common scattering variable (Q-space, d-space, s-space) when the original diffraction patterns are in 2theta-space or time-of-flight-space. How to save selected peaks and/or background for indexing programs. Running the programs from the FPS_Toolbar or from WinPLOTR.

Introduction to the mathematical description of powder diffraction patterns. Peak shapes.
Instrumental resolution of constant wavelength and time-of-flight neutron powder diffractometers.
Sample contribution to broadening (microstructure).

Refinement of powder diffraction patterns without structural model.
Pawley and Le Bail methods.
Limitations and pitfalls.

Ab-initio structure determination using single crystal or powder diffraction.
Direct methods (XLENS) in reciprocal-space and direct-space methods (Simulated annealing within FULLPROF).

Using WINPLOTR for fitting zones of the diffraction pattern. Setting up an instrumental resolution file. Using the Le Bail method for extracting integrated intensities. Preparation of integrated intensity files to be used by the simulated annealing method implemented in FULLPROF.
Data reduction of single crystal data collection: the use of the program DATARED for treating different kind of cases (twins/domains,  propagation vectors).

Structural models: the expressions of structure factors in the case of simple crystal structures, rigid-body constraints, special form factors and symmetry adapted modes. Free parameters of the structural model. Information contained in powder diffraction patterns: introduction to the Rietveld method. The limitations of the least-squares optimisation method. Agreement indices and graphic output.

Strategy for refining structures with single crystal data.
Strategy for Rietveld refinements. Behaviour of the program under an excess of free parameters.
Introduction of constraints and restraints. Inspection of the difference curve in powder diffraction, interpretation of the different features.

Post-refinement calculations: Distances, angles and Bond-Valence sums (programs: Bond_Str and GBond_Str). The programs Fourier and GFourier. Visualisation of structures using FULLPROF Studio.

Setting up an input control file for FULLPROF. The use of EDPCR and text editors. Importing CIF files. Automatic modes of refinement. Hints and tricks. Using the simulated annealing method implemented in FULLPROF. Training using example files distributed within the FULLPROF SUITE.
Complete treatment of a case problem: solving and refining the crystal structure of a perovskite-like material, using x-ray and neutron diffraction data. The use of instrumental resolution function files. Combined refinements. Multi-phase refinements.

Structural phase transitions. Describing crystal structures in terms of symmetry adapted modes. Use of the Bilbao Crystallographic Server (BCS) for solving group theory problems in condensed matter research. Primary and secondary order parameters. Detailed content of the BCS programs PSEUDO, CELLSUB, SYMMODES and AMPLIMODES.

Setting up PCR files from AMPLIMODES. Adapting the generated PCR file to the treatment of real data: simulated annealing, least squares for powders (Rietveld method) and single crystals. Use of sequential refinements for treating phase transitions using the built-in procedure implemented in FULLPROF. Plotting cell parameters and amplitude of modes after running sequential FULLPROF from WINPLOTR.

Examples of building up PCR files from AMPLIMODES. Comparison of the structures of CaTiO₃ and LaMnO₃ at RT in terms of mode amplitudes. General procedures for setting up sequential refinements. Conventions concerning the name of data files. Saving intermediate files for further posterior treatment. Content of the global file my_code.seq. Treatment of the Janh-Teller transition in LaMnO3 using symmetry modes. Other examples of refining crystal structures in terms of symmetry modes: charge ordering in LiMn₂O₄ (neutron powder diffraction), Zener polarons in Pr_0.6Ca_0.4MnO₃ (single crystal neutron diffraction).

The description of molecular crystals using rigid bodies. Molecular and crystal reference frames. Different descriptions of molecules: Cartesian, spherical and cylindrical coordinates for the molecular frame. The Z-matrix description of molecules.
Plastic crystals, free rotators, special form factors using symmetry adapted spherical harmonics.

Free parameters in the rigid body description: position of the centre of molecular frame and Euler angles for setting the global orientation of the molecule. Internal coordinates: torsion angles. Solving molecular crystal structures using simulated annealing and the Z-matrix approach. Advantages and drawbacks of Z-matrices. Alternative approaches using distance and bond angles restraints.

Simultaneous X-ray - neutron refinements.

Importing CIF and converting fractional coordinates of a molecule to a rigid body: use of the utility program Mol2PCR. Molecular editors.
Treatment of powder diffraction data of pharmaceutical compounds. Solving structures by direct space methods, using rigid bodies and/or restraints, from synchrotron x-ray powder diffraction data. Simple examples: urea, citric acid, aspirin, ibuprofen, PPH3, etc.
Examples of crystal structure refinement of molecular solids using neutron powder diffraction: clathrates, small molecules: SF6, thiophene, n-oxy-picoline... Examples of single crystal refinement jointly using neutron and X-ray data.