Making a Linear Molecule Data File
Note: All quantum numbers (spin, J, K...) are input and displayed at double their
actual values to allow for half integral values.
A simple linear
molecule file can be generated from File, New, Linear Molecule.
This initializes the program for a molecule with a band origin of 1000
cm-1and B' = B'' = 1 cm-1. To adjust
the constants (and set the type of vibronic transition) PGOPHER uses select View, Constants.
- If the molecule has a centre of symmetry, click on "Linear
Molecule" and set Symmetric
= "True". You will also
need to set the statistical weights in the same
window. For diatomic molecules with nuclear spin I the values should be:
|
I integral
|
I
half integral
|
SymWt |
(I+1)(2I+1) |
I(I+1) |
AsymWt |
I(I+1) |
(I+1)(2I+1) |
- Adjust the ground state by clicking on the "v=0" entry under
"Ground". The key things
to set are:
- Lambda (to Sigma+, Sigma-, Pi, Delta, ...)
- Overall Spin, S. Remember PGOPHER doubles all quantum
numbers, so for a doublet state enter 1.
- If the molecule is symmetric, set gerade
(True for g, False for u)
- The rotational constant, B
- For non Σ states, the spin orbit coupling constant, A.
- For S ≥ 1 LambdaSS (the spin-spin
coupling constant) may also be important.
- Now switch to the upper state (click on the "v=1" entry under "Excited") . The key things to
set here are:
- The Origin
- All the settings and values listed above under the ground state.