xraydb

library4.5.8pypypi✓ verified 72d ago

XrayDB provides reference data for X-ray interactions with matter, including atomic scattering factors, X-ray absorption cross-sections, fluorescence yields, and more. Version 4.5.8 supports Python >=3.9. Release cadence is irregular, with occasional minor updates.

science

pip install xraydb

github ↗homepage ↗

INSTALL

IMPORT

SIG · XRAYDB

xraydb

sciencepythonv4.5.8

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

XrayDB

✓ from xraydb import XrayDB

Main class used for querying X-ray data.

f1_energies

✓ from xraydb import f1_energies

Returns anomalous scattering factors f1 and f2 given element and energy.

atomic_density

✓ from xraydb import atomic_density

Returns atomic density element.

Basic usage of XrayDB to fetch anomalous scattering factors and absorption cross-sections.

import os from xraydb import XrayDB # Use an API key if required (currently no key needed for local database) db = XrayDB(cache_dir=os.environ.get('XRAYDB_CACHE', '/tmp/xraydb_cache')) # Get anomalous scattering factors for iron at 7 keV energy = 7000 # eV f1, f2 = db.f1_energies('Fe', energy) print(f"f1 = {f1:.3f}, f2 = {f2:.3f}") # Get x-ray absorption cross-section for copper at 10 keV mu = db.mu('Cu', 10000) print(f"mu = {mu:.5e} cm^2/g")

Debug

Known issues

gotchaThe database is bundled with the package; a large download (~100 MB) occurs on first import or use. Ensure sufficient disk space and internet connection.

fix

None (expected behavior).  Alternatively, use system database by setting environment variables or installing separately.

affects: all

gotchaThe database download URL changed in version 4.5.0; older cached databases may cause errors until deleted. If you see "Database version mismatch" after upgrading, remove the cache directory (default ~/.xraydb).

fix

Delete the cache directory: rm -rf ~/.xraydb

affects: >=4.5.0, <4.6.0

deprecatedThe function `get_xraydata` was removed in version 4.0.0 without deprecation. Use `XrayDB` class methods instead.

fix

Use from xraydb import XrayDB; db = XrayDB(); db.mu('Fe', 7000) instead.

affects: >=4.0.0

gotchaThe database file is large (over 100 MB) and may cause slow first-time imports. On low-storage systems, import can fail with insufficient space.

fix

Set an alternative cache directory with XRAYDB_CACHE environment variable or pass cache_dir to XrayDB().

affects: all

Errors

Common errors & fixes

DatabaseError: Database version mismatch. Expected 4.5.0, got 4.4.0

Outdated cached database after upgrading xraydb.

fix

Delete the cache: rm -rf ~/.xraydb and re-run your script.

FileNotFoundError: [Errno 2] No such file or directory: '~/.xraydb/xraydb.sqlite'

Database has not been downloaded or cache directory is missing.

fix

Run your script again; the download will start automatically.  Alternatively, set XRAYDB_CACHE to a writable directory.

ImportError: cannot import name 'get_xraydata' from 'xraydb'

Function removed in xraydb 4.0.0.

fix

Use the XrayDB class: from xraydb import XrayDB; db = XrayDB(); results = db.mu(...)

ValueError: Element 'Uu' not found

Invalid element symbol passed to a function.

fix

Use valid element symbols e.g., 'Fe', 'Cu'.  Case-sensitive.

Upgrade

Version history

4.5.8latest on PyPI · released Jul 18, 2025

Audit

Dependencies

No dependency data recorded yet.

Agent activity

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node

Resources

githubhttps://github.com/xraypy/XrayDB ↗

homepagehttps://github.com/xraypy/XrayDB ↗