Energy Level Plot Window

This window enables energy levels to be plotted for either a particular state or manifold, or for the whole molecule.  It is possible to compare energy levels from the simulated spectrum with observed levels from an experimental spectrum, given a fit (.lin) file (made as described in line position fitting). To do this:
  1. Open the fit file in the Log window.
  2. Select to plot upper state energy levels or to plot lower state energy levels.
  3. Press to display the observed energy levels.
  4. The display is normally clearer if is selected for the calculated energy levels.
Click on an item in the diagram below for more information:



  Adjust plot range to include all energy levels.

  Expand vertical scale.  The required area can first be selected by left-clicking and dragging.

Compress vertical scale

Show a point for each energy level.

Join energy levels with same symmetry with lines.

  Plot both points and lines.

 Do not show observed points.

  Plot upper state observed levels (assuming the lower state energy levels are as calculated).

  Plot lower state observed levels (assuming the upper state energy levels are as calculated).

   (Re)load observations from the clipboard or file.

 Join observed point to calculated point.

Open another energy level window.


State/Manifold/Molecule Selects the object in the object hierarchy to be plotted.
Top Highest energy displayed on the vertical scale.
Bottom Lowest energy displayed on the vertical scale.
Jmax Maximum rotational level (NB values of J are doubled here, whereas J values plotted on the energy level graph are not)
Jmin Minimum rotational level.
Perturbations Checking this box takes perturbations between states into account.
Join Highest
Subtract Subtract the given value time J(J+1) from the plotted points. If you choose a value close to the rotational constant the plots are typically clearer.