  There exist two groups of electron microscopy methods that are capable of
providing three-dimensional (3D) structural information of an object, i.e.,
electron tomography and depth sectioning. Electron tomography is capable of
resolving atoms in all three dimensions, but the accuracy in atomic positions
is low and the object size that can be reconstructed is limited. Depth
sectioning methods give high positional accuracy in the imaging plane, but the
spatial resolution in the third dimension is low. In this work, electron
tomography and depth sectioning are combined to form a method called
multiple-section local-orbital tomography, or nLOT in short. The nLOT method
provides high spatial resolution and high positional accuracy in all three
dimensions. The object size that can be reconstructed is extended to a million
atoms. The present method establishes a foundation for the widespread
application of atomic electron tomography.
