Crate Responsibilities

Each Nucleide crate has a single responsibility and a well-defined place in the workspace dependency graph.

Foundation crates

`linalg`

Isolation facade over the linear-algebra backend. Today it pulls in faer, num-complex, and roxmltree so numeric dependencies do not leak into other crates. Other workspace crates depend on linalg, not on the backend directly.

`nuclei`

Canonical nuclide identification. Owns:

NuclideId: compact u32 representation compatible with legacy integer ids.
Element symbol/number tables.
Name parsing (U235, Am242_m1, Ba137m).
Naming dialects: MCNP ZAID, Serpent, FLUKA, NIST, CINDER, ALARA, SZA.
Particle registry and reaction-name registry (labels, MT mapping, hashes).
Physical data access: AME2020 masses, natural abundances, half-lives.

Capability crates

`material`

Compositions, mixing arithmetic, unit conversions, DOE/PNNL Materials Compendium loading, and materials XML export. Depends on nuclei.

`mcnp-io`

MCNP-family file I/O: xsdir, meshtal, SSW/SURFSRC, PTRAC, WWINP, MCTAL readers; material extraction from input decks; mesh-to-geometry deck generation. Depends on nuclei.

`serpent-io`

Parsers for Serpent MATLAB-style output files (_res.m, _dep.m, _det.m). No internal crate dependencies.

`fluka-io`

FLUKA interface: USRBIN tally reader and MATERIAL/COMPOUND card generation. Depends on nuclei.

`enrichment`

Multicomponent enrichment cascades and SWU analytics. Depends on nuclei and stays independent of material.

`depletion`

CRAM matrix exponential (orders 16 and 48) and depletion-chain XML parsing. Depends on linalg and nuclei.

`vr-tools`

MAGIC weight-window generation and mesh source sampling with alias tables. Depends on mcnp-io (nuclei comes in transitively).

Binding crates

`nucleide-bindings`

PyO3 extension module that exposes workspace crates to Python as nucleide._internal. It is the only crate allowed to depend on pyo3 and the only crate allowed to know about the Python API surface. It depends on most capability crates.

`nucleide-wasm`

wasm-bindgen crate that exposes a subset of the workspace to the browser for the interactive tutorials on the docs site. It is not published to crates.io (the release workflow’s publish list excludes it); the site builds it with wasm-pack.

Dependency rules

Workspace crates may depend on other workspace crates.
Workspace crates must not depend on nucleide-bindings, nucleide-wasm, or pyo3.
nucleide-bindings may depend on workspace crates.
enrichment must not depend on material.

Release order

When publishing to crates.io, publish in dependency order:

linalg
nuclei
material
mcnp-io
serpent-io
fluka-io
enrichment
depletion
vr-tools
nucleide-bindings