Building an amorphous model typically involves a tradeoff between large supercells and classically described inter-atomic potentials, or small cell sizes at a quantum mechanical level of theory, and a limited description of the structure. Intuitively, a high-accuracy inter-atomic potential, large cell size model is the goal, however first principles quantum mechanical calculations using density-functional theory (DFT) scale as 𝑂(𝑁 + ) making these large cell size accurate calculations unfeasible. Previous models of amorphous alumina from first principles are on the order of 50 to 200 atoms, and any of observables such as electronic DOS or chemical shift consider only a single unit cell . Furthermore, these models typically compare to previous experimental work on amorphous alumina, rather than ensuring that the experimental conditions they are comparing to are consistent; given the known interdependence between structure and deposition conditions, especially in the case of amorphous alumina, a direct comparison is imperative, as we will show herein .