  The key to optimizing spatial resolution in a state-of-the-art scanning
transmission electron microscope is the ability to precisely measure and
correct for electron optical aberrations of the probe-forming lenses. Several
diagnostic methods for aberration measurement and correction with maximum
precision and accuracy have been proposed, albeit often at the cost of
relatively long acquisition times. Here, we illustrate how artificial
intelligence can be used to provide near-real-time diagnosis of aberrations
from individual Ronchigrams. The demonstrated speed of aberration measurement
is important as microscope conditions can change rapidly, as well as for the
operation of MEMS-based hardware correction elements that have less intrinsic
stability than conventional electromagnetic lenses.
