Molecule Types Vibrational Structure Vibrational Energy Levels and FranckCondon 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 (n_{i}) 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: (v_{1}+d_{1}/2)^{n1}(v_{2}+d_{2}/2)^{n2}...
For example to add a conventional x_{12}
term set Op =
x, v1 = 1, v2 = 1. 
q

Product of normal mode operators: q_{1}^{n1}q_{2}^{n2}...
n_{1}, n_{2} should
all be >= 0_{
} 
qSigned  Product of normal mode
operators: q_{1}^{n1}q_{2}^{n2}...
with the additional selection rule that:Δv_{1} = n_{1},
Δv_{2} = n_{2},
...
orΔv_{1} = n_{1},
Δv_{2} = n_{2},
...
In this case the signs of n_{1},
n_{2}...
are important. 
Gaussian  Matrix element of exp(bq_{i}^{2}) where b is the Exponent parameter above for the mode with non zero n_{i}. More than one n_{i} can be set nonzero, 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.) 