Building Periodic Systems with the Crystal Editor

The Tools=>PBC menu path and the Crystal Editor button both bring up the PBC window. This tool is used to specify unit cells for periodic systems. In order to use this feature, as well as to perform Periodic Boundary Conditions calculations in Gaussian, you will need some understanding of periodic systems, space groups, and general related terminology. This background is assumed in this section.

There are four buttons at the bottom of the window:

The window contains five panels:

From the highest-level view, a typical process of building a periodic system might proceed as follows:

1: Use the Symmetry panel to specify the number of dimensions and desired space group.

2: Add atoms to the cell, using the mouse or via the Contents panel.

3: Remove any unwanted atoms (e.g., if you used a fragment as a shortcut to creating the necessary atoms).

4: Set the unit cell size, using the Cell panel.

5: Adjust bonding, using the Contents panel if appropriate.

6: Reduce cell contents if appropriate.

7: Specify display properties, using the View panel as desired.

PBC Building Tutorials

Consult the PBC tutorials for more detailed instructions: