Ampac IRC Plot

An Ampac IRC Plot dialog is used to show plots of the energy (Heat of Formation) and RMS Gradient Norm of the energy versus an Intrinsic Reaction 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 IRC calculation, and if the molecule has not been modified.

The IRC 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 IRC Plot dialog is similar in appearance and functionality to a Reaction Path Plot dialog, though the meaning of the plots differ, of course.

An analogous Gaussian IRC Plot is available when Gaussian IRC result files are loaded.

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

Example

The general features and usage of the IRC 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 IRC plot is given below.

Figure 1.  The Ampac IRC 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 IRC calculation.  The two end points of the plot are the minimum energy geometries found by traversing the IRC vector from the transition state.

 

Figure 2.  A view window of a molecule group resulting from an Ampac IRC calculation.  The active molecule, number 6, is the transition state geometry used to start the IRC calculation, as indicated in Figure 1.  The input geometry for an Ampac IRC calculation need not be the exact transition state geometry, but should be reasonably close so Ampac can find it before it starts the IRC.