Define Interface Dialog Box

Define the surface that is to be used for the planar interface on which the disordered system is built.

  • Using
  • Features
  • Additional Resources

Using the Define Interface Dialog Box

When you choose the plane for the interface, you should make sure that it is on the surface (at least approximately), as no changes are made to the substrate. So if you want a particular crystal plane, for example, you should make sure that the crystal plane is exposed (at the surface) in the structure you choose for your substrate.

You can specify a gap on both sides of the disordered system. If they are zero, you will get a "sandwich" system, in which layers of substrate and the amorphous substance alternate and are in contact with each other. Specifying a large gap between the top of the amorphous region and the image of the substrate allows you to simulate a system in 3D that approximates a 2D system.

Define Interface Dialog Box Features

Note: The features available in the dialog box and the default values depend on the application from which it is opened. This topic lists all available features.

Best fit to all atoms option

Select this option to define the interface plane as the best fit to all atoms in the structure. As the fitting on its own will place the plane in the middle of the substrate, the plane is moved after fitting so that it rests on the surface of the structure.

Vector (x, y, z) option and text boxes

Select this option to define the interface as the plane that is perpendicular to the vector specified in the text boxes.

Crystal vector option

Select this option to define the interface as the plane that is perpendicular to one of the crystal vectors and at the surface of the substrate, and select the vector (a, b, or c). The cell is extended in this direction to accommodate the disordered system.

Choose at least 3 atoms to define the plane option

Define the interface plane as the best fit to the chosen atoms. Select Pick and pick the atoms in the Workspace. The plane is fit to the atoms as you pick, after the third atom is picked, and the plane and arrow marker in the Workspace are centered at the centroid of the picked atoms. No adjustment is made to place the plane at the surface of the substrate.

Flip Direction button

Flip the direction of growth of the disordered system. The arrow indicates the direction of growth; the plane indicates the location of the interface between the substrate and the disordered system. If you chose Crystal vector or Best fit to all atoms to define the interface, the opposite side of the structure is used for the interface: the plane is moved in the Workspace to the opposite surface of the substrate structure and the arrow points in the opposite direction. If you picked atoms to define the plane, it is assumed that you chose the desired interface plane, but the direction of growth is incorrect. In this case, the plane stays where it is but the arrow direction changes.

Buffer between surface and components text box

Specify the minimum distance of any atom in the surface to any atom in any molecule in the disordered system. This allows you to create a gap between the substrate and the disordered system.

Buffer between components and surface mirror image in the periodic box text box

Specify the minimum distance of any atom in the substrate in its image in the next cell above the surface to any atom in any molecule in the disordered system. This allows you to create a gap between the top of the disordered system and the next occurrence in that direction of the substrate in a periodic system. By making this value large, you can obtain an approximation to an isolated surface rather than one that is periodic in 3D.

Reset button

Reset the settings to their default values.

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