Energy Level Plot Window
This window can be used to display a wide variety of energy level
plots. The plot below is a typical linear molecule plot, showing the
rotational levels of the ground X 3Σ -state of
SO. Plotted as a function of J,
in shows the F1 F2 and F3 components
as a function of J. Note that
BJ(J+1) has been subtracted from the
vertical scale, so that the deviations from the simple BJ(J+1)
pattern are clear. The actions of the various controls are listed below.
- The status bar at the bottom will show
the co-ordinates
of the mouse at a minimum, and will also normally show information
about calculated and observed points.
- To print the plot right click on the plot and select
"Copy to clipboard" and then paste it into a suitable application.
For Microsoft word, and many other applications it is important to use
"paste special" rather than a simple paste (otherwise the numbers
producing the plot will be pasted, rather than the plot itself).
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Select which states to plot. |
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Open another level Window |
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Write the plotted energy levels to the Log window |
Plot Type
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The options in this group control the overall appearance of
the plot.
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Plot against external field, rather than quantum number. See
Electric or Magnetic Field Plots for
more details.
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Plot a symbol for each level. The key to the symbols will
normally be shown at the top of the plot, and different symbols
indicate different symmetries.
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Join associated levels with lines. The levels joined are
controlled by the three options below.
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Plot both points and lines.
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Choose between starting join process from the highest energy
or lowest energy point |
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Try to join points with related values of quantum numbers |
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Try to join points arising from same state |
Energy Scale
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The options in this group control the vertical scale of the
plot
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Maximum energy in plot |
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Minimum energy in plot |
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Adjust plot range to include all levels |
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Zoom to selected vertical range |
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Compress vertical scale |
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Subtract number × J(J+1) from all energies plotted |
Level Selection
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This group allows levels to be selected by symmetry or some
other quantum numbers. The picture is for a linear molecule; alternate
quantum numbers are selected for other molecule types.
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Select (or not) symmetry to plot |
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Select Ω (linear molecules), Ka (asymmetric tops) |K| (symmetric tops) or v1
(Vibrating molecule).
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Select Fn (linear
molecules), Kc (asymmetric
tops) or Kl (symmetric tops).
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x Axis
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For normal plots, this controls the x axis.
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Select quantum number for x axis |
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Minimum J to include in plot |
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Maximum J to include in plot |
Observed Level Overlay
It is
possible to compare calculated and observed energy levels, with the
"observed" energy levels calculated from measured line positions and
the simulated energy levels for the other state. This requires an
experimental line list (a .lin file), made as described in line position
fitting. To include experimental information:
- Make sure the line list file is set in
the Log window.
- Select
to plot upper
state energy levels or 
to
plot lower state energy levels.
- Press
to display the
observed energy levels.
- The display is normally clearer if is
selected for the calculated energy
levels.
- If the mouse is over an experimental point it's source is
displayed in the status bar; right click offers the following options:
- Edit Point: Open point under cursor in editor if possible.
- Show Line: Centre main plot on transtion
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Plot Upper State Observed Levels |
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Plot Lower State Observed Levels |
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Join observed point to calculated point |
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(Re)load observations |
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When plotting observed energy levels, scale the distance from
the calculated position by this. |
Calculation Adjustment
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This group allows the selected items to be excluded from
calculations
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Exclude perturbations in plotted levels |
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Set how many nuclear and electron spins to exclude from the
calculation |
Line Labels
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Where to place labels on calculated lines. Possible
choices are:
- None
- LeftOut: At left edge of plot, right justified
- LeftIn: At left edge of plot, left justified
- RightIn: At right edge of plot, right justified
- RightOut: At right edge of plot, left justified
- Start: At start of the line
- End: At the end of the line
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Windows