Parallel-beam 4D-STEM tilt series on the metal-organic framework UiO-66

This repository contains data from scanning nanobeam electron diffraction experiments acquired using the 4D Camera installed on the double-aberration-corrected TEAM 0.5 instrument at NCEM. Each directory contains a tilt series of consecutive 4D-STEM scans acquired on a conglomerate of eight UiO-66 nanocrystals, alongside a sequence of simultaneously acquired HAADF images. A near-parallel probe was formed by using a custom 10 μm C2 aperture (Norcada) to access a range of narrow (<0.1 mrad) semiconvergence angles. Using a custom DigitalMicrograph script, 4D-STEM data were acquired in increments of 1 degree with the 4D Camera operating at 87000 frames per second. Each dataset is comprised of 512×512 probe positions and 576×576 detector pixels, resulting in 174 GB of raw data per scan. These raw data were counted and reduced to a sparse, linear-index-encoded electron event representation (EER) in HDF5 format on the NERSC supercomputer, Perlmutter, using the open-source software package stempy. These sparse HDF5 files can be interactively viewed using our open-source python-based software, DuSC Explorer. Experimental parameters for UiO-66: Accelerating voltage 300 kV Semiconvergence angle 0.07 mrad Scan dimensions 512×512 Real-space step size 6.45 nm Estimated probe size (FWHM) 14.4 nm Total illuminated area 22.1 μm^2 Estimated fluence per probe position 1 e- Å^(-2) Total size of raw data 12180 GB Total size of sparsified data 10.5 GB