Knowledge Bank

The spectra of $MnCl4\mathrm{<mrow\; data-mjx-texclass="ORD">2-</mrow>}$, and $CoCl4\mathrm{<mrow\; data-mjx-texclass="ORD">2-</mrow>}$ and $NiCl4\mathrm{<mrow\; data-mjx-texclass="ORD">2-</mrow>}$ have been examined in single and mixed crystals with $ZnCl4\mathrm{<mrow\; data-mjx-texclass="ORD">2-</mrow>}$ at $4\circ K$ using polarized light. The importance of nuclear distortions from perfectly tetrahedral symmetry as well as the effects of spin-orbit coupling and some finer effects of electronic repulsion in the interpretation of these spectra will be discussed.