PP Card

This card defines the phase shift of the excitation between one unit cell and the next for periodic boundary conditions. The unit cell for a PBC calculation is specified with the PE card.

On the Home tab, in the Planes / arrays group, click the  Periodic boundary icon. From the drop-down list, click the  Periodic phase (PP) icon.

Figure 1. The PP - Set phase shift for periodic boundary condition dialog.


Parameters:

Manually specify phase shift
The phase shift is manually specified.
Determine phase shift from plane-wave excitation
When a plane wave is used as excitation the phase difference between the cells cannot be specified, but is determined by the excitation.
Determine phase shift from beam pointing (squint) angle:
The phase shift is determined by specifying the theta and phi angle of the squint angle.
Phase shift in u ^ 1 direction (degrees)
Phase shift in the first direction, u ^ 1 .
Phase shift in u ^ 2 direction (degrees)
Phase shift in the second direction, u ^ 2 .

One dimension:

Theta angle (degrees)
Orientation of the squint angle. The angle, theta, in degrees is the angle between the squint angle and the plane defined by the u ^ 1 vector.

Two dimensions:

Theta angle (degrees)
Orientation of the squint angle. The angle, theta, in degrees is the angle between the squint angle and the u 1 =0 plane.
Phi angle (degrees)
Orientation of the squint angle. The angle, phi, in degrees is the angle between the squint angle and the plane defined by the u ^ 1 vector.
Note that multiple PP cards can be used in a model but only one PE card can be used.