| Abstract Scope |
For complex multi-component atomic-scale systems, ultraviolet and visible light optical properties may serve practical functional purposes and/or be an invaluable tool for characterization. Density functional theory (DFT) based calculations provide support and guidance for experimental observations but, unfortunately, such calculations usually only describe the total model and do not provide more granular detail. Here, we present a newly developed DFT based technique within the orthogonalized linear combination of atomic orbitals (OLCAO) method for decomposing the total optical spectrum of a model into its partial contributions from different selectable subsets of initial-states and final-states. The state subsets may be assembled from different electron spins, orbital types, atomic types, elements, or spatial regions of a model. The method is described and demonstrated for a set of progressively complicated material systems including silicon nitride, amorphous SiO2 glass, and a nanostructural intergranular glassy film model. |