Extended Data Figure 3: DDA EELS simulations of a silver nanocube.
From: Three-dimensional imaging of localized surface plasmon resonances of metal nanoparticles
a, b, DDA EELS simulated as functions of position (as shown by the blue dotted line) for a 100-nm silver cube with rounded corners in vacuum with dielectric function tabulated in ref. 33 (a), and for a 100-nm silver cube with rounded corners in vacuum with dielectric function tabulated in ref. 42 (b). c, 2D tomographic reconstructions of the five spectral features identified in a and b (C1, C2, C3, E and F), made from a tilt series of simulated spectra in which the cube is rotated about a cube axis perpendicular to the beam. The five spectral features correspond to lowest-energy (dipole) corner (C1), higher-energy corner (C2 and C3), edge (E) and face (F) components. We note that the individual components C2 and C3 are not separated if the dielectric tabulation in ref. 42 is used, as in b. Each reconstruction is scaled independently. There are significant negative values only in the reconstruction of the C3 component, which corresponds to a singly degenerate octupole mode. Tomographic reconstructions made from this tilt series were obtained using SIRT41, implemented using the TOMO3D software package43.
