Ampac Path Plot

An Ampac Path Plot dialog is used to show plots of the energy (Heat of Formation) and RMS Gradient Norm of the energy versus Steepest Descent Coordinate for a series of molecules in a molecule group.  This dialog is accessible if the parent view window's current molecule was loaded from an Ampac result file generated from an Ampac Path calculation, and if the molecule has not been modified.

The Path Plot dialog for the active view window is opened and / or activated by selecting "IRC/Path..." from the Results Menu of the main window or the context popup menu of the active view window.

While this dialog is open the current molecule in the parent view window is read-only, i.e., it cannot be modified, though it can be deleted from the molecule group.  When a molecule is deleted from a group, its corresponding point on the plot is simply removed.

An Path Plot dialog is similar in appearance and functionality to an Ampac IRC Plot dialog, though the meaning of the plots differ, of course.

See the Ampac Calculation Setup dialog and the Ampac Manual for details on how to set up Ampac Path calculations and interpret the results.

Example

The general features and usage of the Path Plot dialog can be found in Result Plots and Spectra.  That section includes detailed information on manipulating the plots, such as showing / hiding, zooming, printing, and changing units.  A specific example of an steepest descent path plot is given below.

Figure 1.  The Ampac Path Plot dialog for the molecule group in the view window shown in Figure 2.  The current point in the plots corresponds to the transition state structure used to start the Ampac Path calculation.  The two end points of the plot are the minimum energy geometries found by following the steepest descent path in both directions from the transition state.

 

Figure 2.  A view window of a molecule group resulting from an Ampac Path calculation.  The active molecule, number 8, is the transition state geometry used to start the Path calculation, as indicated in Figure 1.  The input geometry for an Ampac Path calculation need not be the exact transition state geometry, but should be reasonably close so Ampac can find it before it starts the Path.