Molecule Types Vibrational Structure Vibrational Energy Levels and Franck-Condon Factors |
Molecule Types Vibrational Structure Vibrational Energy Levels and Franck-Condon Factors |
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One of these items will be present for each vibrational mode
under each electronic state.
The number is controlled by the nModes at the molecule level.
| Symmetry | Symmetry of this vibrational mode. Note that this setting is shared with every state in the molecule. |
| vMin | Minimum vibrational quantum number for this mode to include in the basis. Note that an implementation restriction in the current version means that values of vMin > 0 are likely to slow calculations for intensities considerably. |
| vMax | Maximum vibrational quantum number for this mode to include in the basis. Note that in more recent versions of the program the default for this is 3 if there are 3 or less vibrational modes, otherwise 0. This avoids asking for very large calculations by accident; if the product over all modes of (vMax+1) is more than 50 or so the calculation is likely to become rather slow. |
| Omega | Vibrational Frequency |
| xOmega | Anharmonic terms. Diagonal
vibrational energy is taken as: Omega(v+d/2) + xOmega(v+d/2)2
+ yOmega(v+d/2)3
+ zOmega(v+d/2)4
+ gll2
where d is the degeneracy of the mode. Note the sign of xOmega - this is
often taken as negative in the Dunham expansion for diatomic
molecules. For polyatomic molecules, xOmega is typically
written as xii,
yOmega as xiii and zOmega as xiiii. For
terms involving more than one mode, like x12 add a Vibrational
Perturbation. |
| yOmega | |
| zOmega | |
| gll | |
| epsOmega | Renner-Teller term |
| lx0 | l matrix elements for first nucleus for this vibrational mode in units of 1/sqrt(amu). Repeated for each nucleus, or absent if the l matrix is not being used to calculate Franck-Condon factors |
| ly0 | |
| lz0 | |
| ... |
Right click on the item in the constants
window for the following operations in addition to the
standard ones: