When adding a Material Property node as an input under a feature or property, you can choose a basic property type or, among other options, a property type defined locally in the current Physics Builder file. The latter choice refers to a Material Property Group node.

A Material Property Group () contains a set of material properties, which can be selected from a list of basic material properties or be customized. When defining a material property group, physics interfaces can use its properties through a material property, and you can also add values to a material library database.

To add an Material Property Group node:

In addition to the settings here, it is also possible to add predefined functions to a built-in property group. The analytic, interpolation, and piecewise analytic function types are available. For interpolation functions, only interpolation tables are allowed. To add a function, right-click the Material Property Group node and select the function type to add from the Functions submenu. A new function node (Analytic, for example) then appears as a subnode under the Material Property Group node.

The Settings window has the following sections:

Each material property group can be categorized under one or several group categories. This simplifies access in the Material node in the Model Builder. To create a new parent for the current property group, click the Create New Parent button () under the Root tree.

Click the Set As Parent button () to choose an existing category as parent. For created categories, you can edit the name in the field under Category, enabled when the Create New Parent button is clicked.

The tree also contains built-in property groups () and categories (), for example the Solid Mechanics property group. Available groups are based on your license.

In the Name field define a string that identifies the property group. It must be unique among all property groups available to materials. COMSOL Multiphysics displays the text entered in the Description field for the property group in the Material properties section of the Material node in the Model Builder.

This section provides possibility to include model inputs to a built-in property group in the Model Builder. Click the Select Quantity button () to open the Physical Quantity dialog box, from which you can choose a physical quantity to add as a model input. Use the other buttons under the table to arrange and edit the table of model inputs if required.

This section provides possibility to include local parameters to a built-in property group in the Model Builder. To add a local parameter, enter a name, a description, and a default expression for the parameter in the Name, Default expression, and Description columns, respectively.