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ADD2026 tutorials

ADD2026 tutorials

Here you will find all of the TOPAS tutorials for use at the hands-on sessions at ADD2026.

The PowerPoint introducing TOPAS can be found at .

The data for all of the tutorials can be downloaded as a single zip file . Download this to your computer and extract it to somewhere you have permissions to edit. The data for each tutorial is in its own folder.

You have hopefully already installed TOPAS and VS Code using the instructions here. There have also been some last-minute additions to make these tutorials flow as easily as possible. Please perform these additional steps now:

  1. Download the latest version of pdf.inc and place it in your TOPAS directory (probably C:\TOPAS7), replacing any previous version.

  2. Download the latest file and place it in your VS Code directory (probably C:\Users\YourUserName\AppData\Roaming\Code\User), replacing any previous version. If you can’t find this, select VS Code+TOPAS setup > Show topas-editor paths and settings from within the VS Code Commands menu and the path to the settings file will pop up on the bottom right of your screen.

 

Not all tutorials will be of relevance to your PDF analysis needs, so feel free to pick and choose which tutorials you follow. We do however recommend all to complete tutorials 1-3 to understand the core theory.

Here you will find a summary of what each tutorial includes:

Tutorial

Summary

Appropriate to:

Prerequisite

Tutorial

Summary

Appropriate to:

Prerequisite

Introduction to TOPAS and VS Code

Basic overview of TOPAS, VS Code and support available.

Reference for all

N/A

  1. PDF Introduction - Basic Refinements

How to run a simple PDF refinement using the PDF macros.

All

N/A

  1. Instrumental Parameters - dQ, alpha and lor

Deeper dive into what the dQ, alpha and Lorentzian functions do and how to asertain them from your PDF instrument.

All

N/A

  1. Correlated Motion - Beq Parameters

Discussion of the beq parameters within PDF refinements and how they differ to the standard thermal parameters in diffraction experiements.

All

N/A

  1. Combining Data - The Power of Dual Refinements

How to use X-ray and neutron PDF data to obtain the best possible fit.

Dual radiation (X-ray/Neutron) source users

1-3

  1. Rigid Bodies - Paracetamol & Well-defined Geometries

How to use the (1) rigid body editor, (2) how to create rigid bodies and (3) how to use rigid bodies in a refinement

Organics, pharmaceuticals and rigid structures

1-3

  1. Structural Disorder - BaTiO3 Modelling Different r Regions

How to simulataneously model low- and high-r regions.

Solid state materials and materials that deviate from the average space group at low-r

1-3

  1. Chemical Disorder - Cu3Au/LiNi0.5Mn1.5O4 Short to Long Range Refinements (STLR)

Fitting local disorder alongside average structure using STLR and box-car type refinements

Materials that exhibit average and local structure that can be modelled using small-box refinements

1-3, 6

  1. Nanostructures - C60 Refinement

Fitting nanostructures by modelling local, average and intermolecular interactions

Nanostructured materials and intermolecular interactions over large length scales

1-3, 7