Theoretical and Computational Chemistry

A directed sampling approach for modelling the structural and electronic properties of amorphous alumina



Advancing the next generation of materials for solid-state devices requires an understanding of their underlying electronic structure; yet the amorphous nature of many materials hinders progress in creating an atomic-level model. One such material is amorphous alumina, which is used to enhance performance in electronic devices from Li-ion batteries to perovskite solar cells. We develop a method which captures local properties of alumina through experimentally informed direct sampling of static configurations from ab initio molecular dynamics. This model is validated with solid-state nuclear magnetic resonance and X-ray absorption spectroscopy, calculated from the first principles level of theory. We finally construct an average electronic density of states for alumina from our model and observe two highly localized states at the conduction band edge.


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Supplementary material

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Supplementary Materials and Methods
The contents of this file include a description of the materials and methods, additional experimental and computational results, and figures to support the main text. These are subdivided into the following sections: 1. Materials and Methods, 2. Results of Fingerprinting in Directed Sampling Approach, 3. NMR Data (Experimental and Computational), 4. XAS spectra and electronic states, 5. Effect of distortions on the electronic states of alumina, 6. Additional spectra for amorphous alumina model at 600K 3.18 g/cm3.