Chapter 26

Discuss Russell-Saunders coupling with the help of suitable examples.

What is the difference between \(L-S\) coupling and \(j-j\) coupling? Discuss the significance of both schemes.

Determine the ground-state term for the following free gaseous atoms: (a) \(\mathrm{C}\) (b) \(\mathrm{N}\) (c) Ca (d) Co (e) \(\mathrm{Zn}\)

Discuss the splitting pattern of following energy terms under the effect of weak \(\mathrm{V}_{\text {oct }}\) and \(\mathrm{V}_{\text {tet. }}\) (a) \({ }^{3} \mathrm{P}\) (b) \({ }^{5} D\) (c) \({ }^{4} F\) (d) \({ }^{6} 5\)

Discuss Hund's rules for the determination of ground-state spectroscopic energy terms.

Discuss selection rules for electronic abosorption spectroscopy.

What do you mean by relaxation of selection rules? Discuss the concept in detail.

What are Orgel diagrams? Discuss their utility in case of coordination complexes.

Determine the \(\Delta_{0}\) values for \(\left[\mathrm{Ni}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) and \(\left[\mathrm{Co}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}\right]^{2+}\) if \(0\left({ }^{3} A_{2 g} \rightarrow{ }^{3} T_{2 g}\right)\) is \(8700 \mathrm{~cm}^{-1}\) and \(\cup\left({ }^{4} T_{1 g} \rightarrow{ }^{4} T_{2 g}\right)\) is \(8000 \mathrm{~cm}^{-1}\). Also draw Orgel diagrams for these complexes.

What are Racah parameters? How are these related with \(d^{n}\) configuration?