2. Introduction

Welcome to the MAterials Simulation Toolkit (MAST)!

MAST is an automated workflow manager and post-processing tool.

MAST focuses on diffusion and defect workflows that use density functional theory. It interfaces primarily with the Vienna Ab-initio Simulation Package (VASP).

However, MAST can be generalized to other workflows and codes.

2.1. The MAST Kitchen

MAST uses kitchen terminology to organize the materials simulation workflow.

• An Ingredient is a single calculation, like a single VASP calculation resulting in a relaxed structure and energy.

• A Recipe is a collection of several ingredients, including information about how the ingredients are combined together.

  • As in a cooking recipe, ingredients may need to be addressed in a logical order, with some ingredients depending on other ingredients.
  • The Recipe section defines this order, or workflow.

When MAST reads an input file, it creates a recipe in the $MAST_SCRATCH directory.

• Many recipes can reside in $MAST_SCRATCH.
• MAST will check and update the recipes in alphanumeric order.

When MAST finds that a recipe is complete, it will move the recipe from $MAST_SCRATCH to $MAST_ARCHIVE.

2.2. Computing in the MAST Kitchen

1. Install MAST (see Installation).

2. Plan your workflow.

   • What are the single calculations you will need (Ingredients)?

   • Which calculations depend on each other and should be grouped into a Recipe?

   • What are all of the conditions for each calculation?

     • Which calculations have a volume change?
     • Which calculations should be run at fixed volume?
     • How fine a kpoint mesh does each calculation need?
     • Etc...

3. Run an example file (see Trying out MAST) to get a feel for how MAST works.

4. Copy and modify an example file for your own workflow.

Please check your output carefully, especially when setting up a new workflow.