Molecule Types Symmetric Tops Transition Moments <Prev Next>

Spherical Transition Moments for Symmetric Tops

This must be used for multiphoton or Raman transitions, and is also appropriate for single photon transitions classified as parallel or perpendicular, as noted below. The "Strength" number is the value of the vibronic only matrix element:
Strength = <stateA| T(k,q) | stateB>
where k is the "Rank" and q the "Component" setting, normally chosen to be >= 0. This has selection rules K(stateA) = K(stateB)+q. The vibronic only matrix element with the opposite sign of q is computed by symmetry. The order of the states (which can be significant in cases involving multiple transition moments) is as displayed in the constants window.

Settings

Rank Rank of transition: 1 for a normal electric dipole transition; see here for multiphoton or Raman transitions
Component Projection quantum number of transition moment. The default is auto, which for simple cases implies taking the only value of the component which gives an allowed transitions. In the standard one photon case it will be 0 for a parallel transition and 1 for a perpendicular transition. For more complicated cases auto will not work and a specifigivenc component must be given.

Parameters

Strength Transition (dipole) moment. For one photon transitions this has units of Debye. Note that the relative intensity is proportional to the square of this value.