Molecule Types Linear Molecules Transition Moments <Prev Next>

Orbital Magnetic Transition Moment

This is appropriate for a magnetic dipole transition moment carried by the electronic orbital angular momentum. In principle the Hamiltonian for this interaction of the electron orbital magnetic moment with an external magnetic field is:


To allow for the most general possible interactions, the Λ dependence is not included in evaluating the matrix element, and must be included in the Strength parameter. In the absence of mixing between electronic states, using Component = 0 with Strength = Λ should give a good starting point. The effective electronic matrix elements are:

    <Λ+Component,SΣ',Ω'|gLμBL|Λ,SΣ,Ω,> =  δΣ'Σ δΩ'Ω+Component Strength

The requirement for Σ' = Σ, δΣ'Σ, is dropped if the electron spin is different between the two states.  The matrix element with Ω' = Ω-Component is derived by symmetry.


Rank Rank of transition: 1 for a normal magnetic dipole transition.
Component Projection quantum number of transition moment: 0 for a parallel transition, 1 for a perpendicular transition. For allowed transitions molecules this will be the change in Λ for the transition; in general it is the change in Ω.


Strength Transition (dipole) moment in units of the Bohr magneton. Note that the relative intensity is proportional to the square of this value.