Electronic transitions in layered hydroxides: Consequences of trigonal distortion of octahedral symmetry

This work describes the assignment of the electronic spectra of metal ions in D(3d )coordination symmetry. Layered hydroxides are a class of materials that host transition metal ions such as Ni2+, Co2+, and Cr3+ in D-3d coordination symmetry. The electronic spectra of these ions in the layered hydroxides exhibit significant fine structure which is assigned to transitions arising from D-3d coordination symmetry. Towards this end, the correlation diagramscomplete or partial, and the resultant Tanabe-Sugano like diagrams for D-3d symmetry are obtained from first principles and supported by DFT based computations. The approach engendered here helps in better understanding of the electronic transitions arising due to lower symmetry. (C) 2020 Elsevier B.V. All rights reserved.