Molecule Types Vibrational Structure Vibrational Energy Levels and Franck-Condon Factors | <Prev Next> |
Add one one these items for every extra term required in the Hamiltonian. To see the actual matrix elements used in any particular case, right click on the perturbation and select "Matrix Elements". The resulting expressions will be displayed in the log window, and should be understood as being multiplied by the Value parameter.
Nucleus | Not used |
SymSelect | Symmetry select |
ScalePrev | Scale factor with respect to preceding perturbation |
Op | Type of perturbation: x, q, qSigned, Gaussian. See below for details |
EffectiveQno | Set to group together states connected by this
perturbation when assigning quantum numbers. |
FromForceField | If true value is set from the "Other
Potential Terms" specified in the internal
coordinates or symmetry
coordinates objects. If not set up in these objects,
the value is forced to zero. |
v1 |
One
entry
per mode; power of each mode (ni) in the overall perturbation
operator |
v2 |
|
... |
Value | Size of perturbation; the expressions and operators given here should be understood to be multiplied by this. |
Exponent | Exponent for Gaussian type perturbation |
x |
Simple diagonal matrix elements with value: (v1+d1/2)n1(v2+d2/2)n2...
For example to add a conventional x12
term set Op =
x, v1 = 1, v2 = 1. |
q
|
Product of normal mode operators: q1n1q2n2...
n1, n2 should
all be >= 0 |
qSigned | Product of normal mode
operators: q1n1q2n2...
with the additional selection rule that:Δv1 = n1,
Δv2 = n2,
...
orΔv1 = -n1,
Δv2 = -n2,
...
In this case the signs of n1,
n2...
are important. |
Gaussian | Matrix element of exp(-bqi2)
where b is the Exponent parameter
above for the mode with non zero ni. More than one ni can be
set non-zero, though this is probably not useful. |
qp |
Product of normal mode momentum operators:
Values of n < 0 are taken as the corresponding
position operators. (Not currently implemented for
degenerate modes.) |