README.md

metadata

license: mit
tags:
  - electron-microscopy
  - 4D-STEM
  - materials-science
  - quantem
pretty_name: quantem-data

quantem-data

Reference electron-microscopy datasets (gold 4D-STEM and HAADF) for browsing and learning with quantem.widget. This repo just hosts the data — all instructions live in one place:

How to download and use this data: follow the Download data tutorial in the quantem.widget docs. One call per dataset:

from quantem.widget import Show4DSTEM
from quantem.widget.datasets import show4dstem_gold

Show4DSTEM(show4dstem_gold())

Layout — two trees:

• widget-tutorials/<widget>/<dataset>/<size>/ — baseline tutorial bundles for the core widgets (show1d/, show4dstem/, showfolder/; data shared by Show2D and Show3D lives under shared/). These back the one-call loaders in quantem.widget.datasets and the Colab workshops. Baseline tutorials only — real work uses your own data.
• 4dstem/, haadf/ — full-size originals (Arina h5, Velox EMD) for power users.

Every NumPy bundle ships a meta.json (shape, dtype, sampling, units, optics) next to data.npy.

Workshop notebooks (Google Colab, no local install): Show4DSTEM demo · Workshop v1

Acquisition parameters

The 20260423 drift session's optics are confirmed via the session's own HAADF EMD (AccelerationVoltage, BeamConvergence, CameraLength). 4D-STEM scan_sampling is an operator pattern from a sibling SSB session — the drift acquisition itself was never per-file calibrated.

dataset	voltage	probe	CL	scan	scan sampling	det pitch	mag
haadf/gold_haadf_npy	300 kV ✓	30 mrad ✓	91 mm ✓	4096² image	0.0186 nm/px	n/a	FOV 76.2 nm
4dstem/gold_512_npy_bin8	300 kV ✓	30 mrad ✓	91 mm ✓	512²	0.5 Å (op)	3.68 mrad/px	unknown
4dstem/gold_512_npy_bin4	300 kV ✓	30 mrad ✓	91 mm ✓	512²	0.5 Å (op)	1.84 mrad/px	unknown
4dstem/gold_512	300 kV ✓	30 mrad ✓	91 mm ✓	512²	0.5 Å (op)	0.46 mrad/px	unknown
4dstem/gold_30mrad1.3mx04…09	300 kV	30 mrad	91 mm	smaller	(session yaml)	0.46 mrad/px	1.3 Mx
haadf/gold_haadf.emd	300 kV ✓	30 mrad ✓	91 mm ✓	4096² image	0.0186 nm/px	n/a	FOV 76.2 nm

✓ = confirmed via EMD/yaml. (op) = operator pattern, not file-certified.

License

MIT — free to use for anything. Citing quantem.widget in publications is appreciated.