A re-bin function using Gatan GMS software was utilized to try and improve the signal: noise ratio of the EELS data. This function consists of summing the intensities of neighboring pixels into a single pixel. The number of pixels within the data set is subsequently reduced. In this analysis the horizontal (x-component) of a data set was summed into one pixel and the number of vertical (y-components) was not changed. For example, in Griffin (Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States) for providing CONTCAR files from reference which were used in initial DFT calculations. The calculations were performed using the high-performance computing facilities of the Tyndall National Institute. The authors also acknowledge access to computing resources at the Irish Centre for High-End Computing (ICHEC).