Installation

Curie is available through the Python Package Index, which allows installation using Python’s standard command line utility pip. Assuming Python and pip are installed already, you can install Curie with the command:

pip install --user curie

or:

python -m pip install --user curie

If you’d like to install the most recent (unreleased) version of Curie, you can clone the Curie GitHub repository and install it from the source tree:

git clone https://github.com/jtmorrell/curie.git
python -m pip install --user ./curie

Nuclear data

Curie downloads the nuclear data files it needs the first time they are used: each database is fetched from the curie data release on first access, verified against its published SHA256 checksum, and stored in a per-user data directory. The large cross-section libraries (ENDF and the TENDL variants) are fetched in small per-target pieces, so looking up one reaction downloads well under a MB rather than a 37-748 MB library. No action is needed to make this happen — the first ci.Reaction(...) or ci.Isotope(...) just works.

To prepare a machine for offline use (or to pre-populate the data directory in one step), download everything explicitly:

import curie as ci
ci.download()

If your data files are stale or corrupted, re-download them with:

ci.download(overwrite=True)

The data directory follows your platform’s convention: ~/.local/share/curie on Linux, ~/Library/Application Support/curie on macOS, and %LOCALAPPDATA%\curie on Windows. To place the data somewhere else — a shared network drive, an air-gapped machine’s data directory — set the CURIE_DATA_DIR environment variable; Curie will use that directory for all of its data. On an air-gapped machine, copy the data directory from a connected machine (or the individual .db files from the curie data release) into CURIE_DATA_DIR.

On a shared (multi-user) machine, an administrator can instead populate the site-wide data directory once — /usr/local/share/curie on Linux, /Library/Application Support/curie on macOS, C:\ProgramData\curie on Windows — and Curie will use those files read-only in place from every account, with nothing downloaded or duplicated per user. Files in the site-wide directory (like those in CURIE_DATA_DIR) are trusted as provided: keep them in sync with the data release matching the installed Curie version when upgrading.

Data installed by Curie versions before 0.1.0 (inside the package’s own directory) is found and adopted into the cache automatically — nothing is re-downloaded after an upgrade.