Question

explains (what’s that )Crystal field and Jahn Teller effect??

Answer 1

The Jahn-Teller effect is an important mechanism of spontaneous symmetry breaking in molecular and solid-state systems which has far-reaching consequences in different fields. It describes the geometrical distortion of molecules and ions that result from certain electron configurations. It essentially states that any non-linear molecule with a spatially degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy, because the distortion lowers the overall energy of the species. For a description of another type of geometrical distortion that occurs in crystals with substitution impurities Crystal field theory describes the breaking of degeneracies of electron orbital states, usually d or f orbitals, due to a static electric field produced by a surrounding charge distribution (anion neighbours) According to crystal field theory, the interaction between a transition metal and ligands arises from the attraction between the positively charged metal cat ion and the negative charge on the non-bonding electrons of the ligand. The theory i4 developed by considering energy changes of the five degenerated- orbitals upon being surrounded by an array of point charges consisting of the ligands