Abstract:
A small probe centered on an atomic column excites the bound and unbound states of the
two-dimensional projected potential of the column. It has been argued that, even when several states are
excited, only the 1s state is sufficiently localized to contribute a signal to the high-angle detector. This article
shows that non-1s states do make a significant contribution for certain incident probe profiles. The contribution
of the 1s state to the thermal diffuse scattering is calculated directly. Sub-Ångstrom probes formed by
Cs-corrected lenses excite predominantly the 1s state and contributions from other states are not very large. For
probes of lower resolution when non-1s states are important, the integrated electron intensity at the column
provides a better estimate of image intensity.
