Changes in the electronic structure of cerium due to variations in close packing

Here we use electron energy-loss spectroscopy in a monochromated transmission electron microscope with 100 meV energy resolution and 2 Å spatial resolution to show that the electronic structure of face centered cubic γ and double hexagonal close-packed β cerium are considerably different, contrary to previous assumptions in literature. These results are supported by synchrotron-radiation-based x-ray absorption, multielectronic atomic spectral simulations, and local density approximation calculations, illustrating that changes in {111} stacking sequences can drive substantial electronic changes in close-packed phases of cerium that have a similar atomic volume.