  We extract the dynamics implicit in an algebraic fitted model Hamiltonian for
the deuterium chromophore's vibrational motion in the molecule CDBrClF. The
original model has 4 degrees of freedom, three positions and one representing
interbond couplings. A conserved polyad allows in a semiclassical approach the
reduction to 3 degrees of freedom. For most quantum states we can identify the
underlying motion that when quantized gives the said state. Most of the
classifications, identifications and assignments are done by visual inspection
of the already available wave function semiclassically transformed from the
number representation to a representation on the reduced dimension toroidal
configuration space corresponding to the classical action and angle variables.
The concentration of the wave function density to lower dimensional subsets
centered on idealized simple lower dimensional organizing structures and the
behavior of the phase along such organizing centers already reveals the atomic
motion. Extremely little computational work is needed.
