Dr. Probe: A software for high-resolution STEM image simulation.

The Dr. Probe software for multislice simulations of STEM images is introduced, and reference is given of the applied methods. Major program features available with the graphical user interface version are demonstrated by means of a few examples for bright-field and dark-field STEM imaging as well as simulations of diffraction patterns. The numerical procedure applied for the simulation of thermal-diffuse scattering by the frozen-lattice approach is described in detail. Intensity variations occurring in simulations with atomic-column resolution due to frozen-lattice variations are discussed in the context of atom counting. It is found that a significant averaging over many lattice configurations with different random atomic displacements is required to prevent atom-counting bias from simulations. A strategy is developed for the assessment of the amount of required averaging based on the estimated signal variance and the expected signal gain per atom in a column.