Salient features of Tanabe Sugano diagram.

The results of the evaluation of energies of various level in going from the weak field to strong cases are presented in graphical form in the Tanabe - Sugano diagram.

2) The Tanabe - Sugano diagrams are commonly used for the interpretation of the spectra including both weak & strong fields.

3) The actual coordination are Dq/B for the horizontal axis and E/B for the vertical axis.

4) The energy of the ground state is represented by the horizontal base line (ground state as the constant reference).

5) Configuration interaction is included as bending of lines for the excited states.

6) The energy of states with the spin multiplicity different from that of the ground state are also represented.

7) For d1-3 & d8-9 systems, the Tanabe - Sugano diagram sare qualitatively similar to Orgel diagram because the ground term doesn't change whatever the field. For d4-7 system there is a discontinuity in the Tanabe - Sugano diagram shown by the vertical line indicating a change from a high spin to low spin case. At this point the ground term also changes.

8) The quantities E/B and Dq/B are plotted because they enable one to convert the equation for the energy into a convenient form of plotting.