Inputs, variables and outputs

#Decide where each value comes from

Workflow data can come from run inputs, fixed node settings, upstream results or environment variables. Decide which values should change between runs before defining fields and references.

#Define run inputs

1. Open a workflow in Material Expert, select User Input, and open its input settings.
2. Add a field, choose its type and enter a variable name.
3. Configure a display name, default, required status and limits as needed.
4. Save the field and select it in downstream parameters that use it.

The variable name identifies the reference; the display name helps the person completing the form. Use meaningful names such as structure_file or sample_label, and keep names unique within the node.

Available constraints depend on the type: text length, numeric bounds, selectable choices, or file count, size and extensions. Match them to the downstream node's requirements.

The option to hide a field and use its default is useful for values that do not need to appear in each run form. Check the default first. Open Test run → Run inputs to inspect the resulting form.

#Select a structure source

Structure Input supplies a structure, and subsequent nodes can reference upstream structure results. Distinguish the original, prepared and transformed structures.

For a calculation after supercell generation, select the transformation node's structure output. Check both the source node and field, especially when the workflow branches.

#Switch between values and references

Supported parameters offer Value and Variable modes. Value stores a fixed setting in the node; Variable selects an available source.

If a variable is missing, check that its source is connected, its field still exists and the types are compatible. After changing a field type or removing a source field, update references and run checks again.

#Configure environment variables and inspect system variables

Open Environment variables in the toolbar, add a name, type and value, then reference it in node settings. Names start with a letter or underscore and may contain letters, digits and underscores, up to 64 characters.

Remove node references before deleting an environment variable that is in use. Use a user input field for values that should be entered for each run.

System variables lists platform-managed field definitions. They are read-only and do not require manual creation or editing.

#Select final outputs

Select Output, add output fields and choose a source for each. Expose the structure, files, cell information and validation separately when useful.

Connecting a processing node to Output does not select the fields to display. Save and use Check to confirm output bindings before running the workflow.