Displaying the averaged potential chart for work function calculations
The CASTEP Analysis dialog can be used to generate plots of the change in electrostatic potential through a slab, which is related to the energy required to remove an electron from the bulk into the vacuum (the work function). The plots are created by averaging the electrostatic potential in the planes perpendicular to the slab normal.
Work function can only be calculated for structures constructed in a slab geometry so that they contain atomic planes separated by a vacuum layer.
The averaged electrostatic potential is reported along the fractional coordinate of the unit cell in the direction of the vacuum. The Fermi level is reported on the work function chart.
To create an averaged potential chart
- Choose Modules | CASTEP | Analysis from the menu bar to open the CASTEP Analysis dialog.
- Select Potentials from the list of properties.
- Make the 3D Atomistic document containing the 3D periodic slab the active document.
- Use the Results file selector to pick the results file.
- Select the Potential field from the dropdown list.
- Optionally check the View isosurface on import checkbox.
- Click the Import button.
- A new chart document,
seedname Potential Profile.xcd, is created in the results folder and becomes the active document. The selected potential field is imported into the 3D Atomistic document and may be displayed as an isosurface.