Tomographic surface phonon EELS experiments and reconstruction: (a) HADF images, plane view and tilted view by 400 mrad, of a MgO nanocube of 190 nm edge length; (b) selected spectra recorded at positions indicated in (a) exhibiting maxima fespectively at 68, 69 and 78 meV; (c) 3D vectorial reconstruction of the EMLDOS emphasizing the corner, edge and face localization of the modes I, II and III, the needles indicate the direction of the polarization while the colors indicate the intensity, from red to yellow (courtesy X. Li et al. [153]).