Symmetric Top 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:
Degenerate states in a symmetric top can be
thought of as having approximately one unit of angular momentum.
To allow for the most general possible interactions, the l
dependence is not included in evaluating the matrix element, and
parameter will be essentially gLl.
See MNR Ashfold, RN Dixon, N Little, RS Stickland and CM Western,
J. Chem. Phys. 89 1754 (1988) for an example
||Rank of transition - 1 for a normal magnetic dipole
||Projection quantum number of transition moment - 0 for a
parallel transition, 1 for a perpendicular transition. This
gives the selection rule on the vibronic angular momentum, l.
||Transition (dipole) moment in units of the Bohr
magneton. Note that the relative intensity
is proportional to the square of this value.