Nuclides & nuclear data

Explore nuclide identifiers, name dialects, and built-in nuclear data.

Nucleide identifies nuclides by a canonical (Z, A, state) tuple and maps it to and from the many naming conventions used by transport, activation, and decay codes.

Nuclide identifiers

A nuclide is fully described by:

• Z — proton number.
• A — mass number (total protons + neutrons).
• state — isomeric state (0 = ground, 1 = first metastable, …).

The canonical integer forms include:

Nuclear data lookups

The nuclei crate bundles atomic masses from AME2020, natural abundances, and decay data. Enter a nuclide below to see every identifier and data value.

Common naming dialects

Different codes expect different strings. Nucleide can convert a single identifier into:

• Serpent: U-235
• MCNP ZAID: 92235
• NIST: 235U
• ALARA: u:235
• FLUKA: 235-U (via fluka())
• CINDER: numeric Cinder ID

Free-form names, decay branches, and isomer masses (Python-only)

The Python nuclei surface resolves free-form spellings symbol-first then mass-first (241Pu → Pu241, Ba-137m → Ba137_m1, Ir-192n → Ir192_m2; bare symbols rejected), lists ENDF/B-VIII.0 per-branch (daughter, fraction, mode) rows via decay_branches / decay_branch_fraction, and carries isomer masses (each isomer tape’s File-1 MT451 excitation energy over the AME2020 ground state, so Ba137_m1 outweighs Ba137; tapeless isomers fall back to the ground state). See the Run depletion tutorial for a worked snippet.

See also

• Theory: Nuclear data
• Crate docs: crates/nuclei/src/lib.rs